Murata Electronics North America 2410G Modular 2.4 GHz Transceiver User Manual G3

Murata Electronics North America Modular 2.4 GHz Transceiver G3

User Manual

WIT24102.4GHz Spread Spectrum Wireless Industrial TransceiverIntegration Guide3079 Premiere Pkwy Ste 140Duluth, Georgia 30097www.cirronet.com+1 (678) 684-2000
Important Regulatory InformationCirronet Product FCC ID: HSW-2410G IC 4492A-2410GFCC s MPE RequirementsInformation to user/installer regarding FCC s Maximum Permissible Exposure (MPE) limits.Notice to users/installers using the 24 dBi parabolic dish antenna in conjunction with all CirronetRF products. FCC rules limit the use of this antenna, when connected to Cirronet RF products for point-to-pointapplications only. It is the responsibility of the installer to ensure that the system is prohibited frombeing used in point-to-multipoint applications, omni-directional applications, and applications where thereare multiple co-located intentional radiators transmitting the same information. Any other mode ofoperation using this antenna is forbidden.This module shall not be co-located inside a device with another transmitter. In the caseof location with other devices at a fixed site installation, Users and installers must beprovided with appropriate antenna installation instructions and transmitter operatingconditions, including antenna co-location requirements of §1.1307(b)(3), for satisfyingRF exposure compliance.Note: This unit has been tested and found to comply with the limits for a Class B digital device,pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable protectionagainst harmful interference when the equipment is operated in a commercial environment. Thisequipment generates, uses, and can radiate radio frequency energy and, if not installed and usedin accordance with the instruction manual, may cause harmful interference to radiocommunications. Operation of this equipment in a residential area is likely to cause harmfulinterference in which case the user will be required to correct the interference at their expense.
Notice to users/installers using the following fixed antennas, with Cirronet RF products:Andrews 24dBi parabolic dishAndrews 18dBi parabolic dishCushcraft 15dBi Yagi,Mobile Mark 14dBi Corner Reflector,Mobile Mark 9dBi Corner ReflectorThe field strength radiated by any one of theseantennas, when connected to Cirronet RFproducts, may exceed FCC mandated RFexposure limits. FCC rules requireprofessional installation of these antennas insuch a way that the general public will not becloser than 2 m from the radiating aperture ofany of these antennas. End users of thesesystems must also be informed that RFexposure limits may be exceeded if personnelcome closer than 2 m to the apertures of any ofthese antennas. Notice to users/installers using the following mobile antennas, with Cirronet RF products:Mobile Mark 12dBi omni-directional,Mobile Mark 9dBi omni-directional,MaxRad 5dBi whip,Cirronet Patch antenna,Ace 2dBi dipole,Mobile Mark 2dBi StubThe field strength radiated by any one of theseantennas, when connected to Cirronet RFproducts, may exceed FCC mandated RFexposure limits. FCC rules require professionalinstallation of these antennas in such a waythat the general public will not be closer than20 cm from the radiating aperture of any ofthese antennas. End users of these systemsmust also be informed that RF exposure limitsmay be exceeded if personnel come closerthan 20 cm to the apertures of any of theseantennas.
Declaration of ConformityWarning! The RLAN transceiver within this device uses a band of frequencies that are not completely harmonizedwithin the European Community. Before using, please read the European Operation Section of the Products User’sGuide for limitations.0889 is the identification number of RADIO FREQUENCY INVESTIGATION LTD - Ewhurst Park, Ramsdell RG265RQ Basingstoke, United Kingdom – the Notified Body having performed part or all of the conformity assessment onthe product.The WIT2410 to which this declaration relates is in conformity with the essential requirements of the R&TTEdirective 1999/5/EC and complies with the following standards and/or other normative documents:For Interfaces For RLAN TransceiverEN 55022EN 55024EN 300 328EN 301 489 -1, -17EN 60950Use Within the European UnionThe WIT2410 is intended for use within the European Community States and in the following non-European UnionStates: Norway & SwitzerlandUse of the WIT2410 in FranceWhen used in France, the WIT2410 can only be operated with the France hopping pattern selected. This isaccomplished by setting the pe parameter to 1. Refer to European Union Settings in this manual for details.Canadian Department of Communications Industry Canada (IC) NoticeCanadian Department of Communications Industry Canada (IC) NoticeThis apparatus complies with Health Canada’s Safety Code 6 / IC RSS 102."To prevent radio interference to the licensed service, this device is intended to beoperated indoors and away from windows to provide maximum shielding. Equipment (orits transmit antenna) that is installed outdoors may be subject to licensing."ICES-003This digital apparatus does not exceed the Class B limits for radio noise emissions fromdigital apparatus as set out in the radio interference regulations of Industry Canada.Le présent appareil numérique n'émet pas de bruits radioélectriques dépassant les limites applicables aux appareilsnumériques de Classe B prescrites dans le règlement sur le brouillage radioélectrique édicté par Industrie Canada.NOTE!Any changes of modifications not expressly approved by the party responsible for compliance could void the user’sauthority operate the equipment.
TABLE OF CONTENTS1. INTRODUCTION ......................................................................................................................11.1. Why Spread Spectrum?.........................................................................................................11.2. Frequency Hopping vs. Direct Sequence..............................................................................22. RADIO OPERATION ................................................................................................................52.1. Synchronization and Registration........................................................................................52.2. Data Transmission................................................................................................................62.2.1. Point-to-Point .............................................................................................................62.2.2. Point-to-Multipoint.....................................................................................................72.2.3. Handle Assignment ....................................................................................................72.2.4. TDMA Operation.......................................................................................................82.2.5. Full Duplex Communication....................................................................................102.2.6. Error-free Packet Transmission Using ARQ............................................................102.3. Modes of Operation............................................................................................................112.3.1. Control and Data Modes...........................................................................................112.3.2. Sleep Mode...............................................................................................................112.3.3. Low Power Mode and Duty Cycling........................................................................122.3.4. RF Flow Control Mode ............................................................................................122.3.5. Co-Existing with 802.11b Networks........................................................................132.3.6. European Union Settings..........................................................................................133. PROTOCOL MODES...............................................................................................................14Note on Using Protocol Mode 4..........................................................................................163.1.1. Data Packet...............................................................................................................173.1.3. Connect Packet.........................................................................................................183.1.4. Disconnect Packet (base only, receive only)...........................................................184. MODEM INTERFACE.............................................................................................................194.1. Interfacing to 5 Volt Systems.............................................................................................204.2. Evaluation Unit and OEM Module Differences.................................................................204.3. Three Wire Operation.........................................................................................................204.4. Power-On Reset Requirements ..........................................................................................215. MODEM COMMANDS...........................................................................................................225.1. Serial Commands ...............................................................................................................225.2. Network Commands...........................................................................................................235.3. Protocol Commands...........................................................................................................265.4. Status Commands...............................................................................................................295.5. Memory Commands...........................................................................................................305.6. Modem Command Summary.............................................................................................316. WIT2410 DEVELOPER’S KIT................................................................................................327. WinCOM...................................................................................................................................337.1. Starting the program...........................................................................................................35
7.2. Function Keys ....................................................................................................................387.3. WinCom Tools...................................................................................................................397.4. Script Commands...............................................................................................................417.5. Demonstration Procedure...................................................................................................438. Troubleshooting.........................................................................................................................449. APPENDICES...........................................................................................................................469.1. Technical Specifications ....................................................................................................469.1.1 Ordering Information..................................................................................................469.1.2. Power Specifications................................................................................................469.1.3. RF Specifications......................................................................................................469.1.4. Mechanical Specifications........................................................................................469.2. Serial Connector Pinouts....................................................................................................479.3. Approved Antennas............................................................................................................479.4. Technical Support..............................................................................................................489.5. Reference Design...............................................................................................................499.6.1. Mechanical Drawing – WIT2410M4 (Pins Down).........................................................509.6.2. Mechanical Drawing – WIT2410S4 (Pins Up)...............................................................5110. Warranty..................................................................................................................................52
WIT2410 2000- 2005 Cirronet Inc 1M-2410-0000 Rev F1. INTRODUCTIONThe WIT2410 radio transceiver provides reliable wireless connectivity for eitherpoint-to-point or multipoint applications. Frequency hopping spread spectrumtechnology ensures maximum resistance to noise and multipath fading and robustness inthe presence of interfering signals, while operation in the 2.4GHz ISM band allowslicense-free use and worldwide compliance. A simple serial interface supportsasynchronous data up to 230400 bps. An on-board 3 KB buffer and an error-correctingover-the-air protocol provide smooth data flow and simplify the task of integration withexisting applications.- Multipath fading imperviousfrequency hopping technologywith 75 frequency channels(2401-2475 MHz).-Supports point-to-point ormultipoint applications.-Meets FCC rules 15.247 and ETS300.328 for worldwide license-free operation.-Superior range to 802.11 wirelessLAN devices.-Transparent ARQ protocolw/3KB buffer ensures dataintegrity.-Digital addressing supports up to64 networks, with 62 remotes pernetwork.-Low power 3.3v CMOS signals-Simple serial interface handles bothdata and control at up to 230400 bps. -Fast acquisition typically locksto hopping pattern in 2 secondsor less.-Selectable 10 mW or 100 mWtransmit power.-Support for diversity antenna.-Built-in data scrambling reducespossibility of eavesdropping.-Nonvolatile memory storesconfiguration when poweredoff.-Smart power managementfeatures for low currentconsumption.-Dynamic TDMA slotassignment that maximizesthroughput.1.1. Why Spread Spectrum?The radio transmission channel is very hostile, corrupted by noise, path loss andinterfering transmissions from other radios. Even in a pure interference-freeenvironment, radio performance faces serious degradation through a phenomenonknown as multipath fading. Multipath fading results when two or more reflectedrays of the transmitted signal arrive at the receiving antenna with opposing phase,thereby partially or completely canceling the desired signal. This is a problemparticularly prevalent in indoor installations. In the frequency domain, a multipath
WIT2410 2000- 2005 Cirronet Inc 2M-2410-0000 Rev Ffade can be described as a frequency-selective notch that shifts in location andintensity over time as reflections change due to motion of the radio or objects withinits range. At any given time, multipath fades will typically occupy 1% - 2% of the2.4 GHz band. This means that from a probabilistic viewpoint, a conventional radiosystem faces a 1% - 2% chance of signal impairment at any given time due tomultipath.Spread spectrum reduces the vulnerability of a radio system to interference fromboth jammers and multipath fading by distributing the transmitted signal over alarger region of the frequency band than would otherwise be necessary to send theinformation. This allows the signal to be reconstructed even though part of it may belost or corrupted in transit.Figure 1Narrowband vs. spread spectrum in the presence of interference1.2. Frequency Hopping vs. Direct SequenceThe two primary approaches to spread spectrum are direct sequence (DS) andfrequency hopping (FH), either of which can generally be adapted to a givenapplication. Direct sequence spread spectrum is produced by multiplying thetransmitted data stream by a much faster, noise-like repeating pattern. The ratio bywhich this modulating pattern exceeds the bit rate of the baseband data is called theprocessing gain, and is equal to the amount of rejection the system affords againstnarrowband interference from multipath and jammers. Transmitting the data signalas usual, but varying the carrier frequency rapidly according to a pseudo-randompattern over a broad range of channels produces a frequency hopping spectrumsystem.
WIT2410 2000- 2005 Cirronet Inc 3M-2410-0000 Rev FFigure 2Forms of spread spectrumOne disadvantage of direct sequence systems is that due to spectrum constraints andthe design difficulties of broadband receivers, they generally employ only a minimalamount of spreading (typically no more than the minimum required by the regulatingagencies). For this reason, the ability of DS systems to overcome fading and in-bandjammers is relatively weak. By contrast, FH systems are capable of probing theentire band if necessary to find a channel free of interference. Essentially, thismeans that a FH system will degrade gracefully as the channel gets noisier while aDS system may exhibit uneven coverage or work well until a certain point and thengive out completely.Because it offers greater immunity to interfering signals, FH is often the preferredchoice for co-located systems. Since direct sequence signals are very wide, theytend to offer few non-overlapping channels, whereas multiple hoppers mayinterleave with less interference. Frequency hopping does carry some disadvantagein that as the transmitter cycles through the hopping pattern it is nearly certain tovisit a few blocked channels where no data can be sent. If these channels are thesame from trip to trip, they can be memorized and avoided; unfortunately, this isgenerally not the case, as it may take several seconds to completely cover the hopsequence during which time the multipath delay profile may have changedsubstantially. To ensure seamless operation throughout these outages, a hoppingradio must be capable of buffering its data until a clear channel can be found. Asecond consideration of frequency hopping systems is that they require an initialacquisition period during which the receiver must lock on to the moving carrier ofthe transmitter before any data can be sent, which typically takes several seconds. Insummary, frequency hopping systems generally feature greater coverage and channelutilization than comparable direct sequence systems. Of course, otherimplementation factors such as size, cost, power consumption and ease ofimplementation must also be considered before a final radio design choice can bemade.
WIT2410 2000- 2005 Cirronet Inc 4M-2410-0000 Rev FAs an additional benefit, RF spectrum has been set aside at 2.4 GHz in mostcountries (including the U.S.) for the purpose of allowing compliant spread spectrumsystems to operate freely without the requirement of a site license. This regulatoryconvenience alone has been a large motivation for the industry-wide move towardspread spectrum.
WIT2410 2000- 2005 Cirronet Inc 5M-2410-0000 Rev F2. RADIO OPERATION2.1. Synchronization and RegistrationAs discussed above, frequency hopping radios periodically change the frequency atwhich they transmit. In order for the other radios in the network to receive thetransmission, they must be listening to the frequency over which the current transmissionis being sent. To do this, all the radios in the net must be synchronized and must be set tothe same hopping pattern.In point-to-point or point-to-multipoint arrangements, one radio module is designated asthe base station. All other radios are designated remotes. One of the responsibilities ofthe base station is to transmit a synchronization signal to the remotes to allow them tosynchronize with the base station. Since the remotes know the hopping pattern, once theyare synchronized with the base station, they know which frequency to hop to and when.Every time the base station hops to a different frequency, it immediately transmits asynchronizing signal.When a remote is powered on, it rapidly scans the frequency band for the synchronizingsignal. Since the base station is transmitting over 75 frequencies and the remote isscanning 75 frequencies, it can take several seconds for a remote to synch up with thebase station.Once a remote has synchronized with the base station, it must request registration fromthe base station. The registration process identifies to the base station the remotes fromwhich transmissions will be received and not discarded. Registration also allows trackingof remotes entering and leaving the network. The base station builds a table of serialnumbers of registered remotes. To improve efficiency, the 24-bit remote serial number isassigned a 6-bit “handle” number. Two of these are reserved for system use, thus eachbase station can register 62 separate remotes. This handle is how user applications willknow the remotes. Note that if a remote leaves the coverage area and then re-enters, itmay be assigned a different handle.To detect if a remote has gone offline or out of range, the registration must be “renewed”once every 256 hops. Registration is completely automatic and requires no userapplication intervention. When the remote is registered, it will receive several networkparameters from the base. This allows the base to automatically update these networkparameters in the remotes over the air. Once a parameter has been changed in the base, itis automatically changed in the remotes. The parameters automatically changed are hopduration and the duty cycle.At the beginning of each hop, the base station transmits a synchronizing signal. After thesynchronizing signal has been sent, the base will transmit any data in its buffer unlessdata transmit delay has been set. The data transmit delay parameter allows for thetransmission of groups of continuous data in transparent mode (protocol mode 0). Theamount of data that the base station can transmit per hop is determined by the base slot
WIT2410 2000- 2005 Cirronet Inc 6M-2410-0000 Rev Fsize parameter. The maximum amount of data sent by a base station per hop is 208 bytes.If there is no data to be sent, the base station will not transmit until the next frequency.The operation for remotes is similar to the base station without the synchronizing signal.The amount of data a remote can send on one hop is dependent upon the hop duration,the base slot size and the number of registered remotes. 212 bytes per hop is themaximum data length a remote can transmit per hop, subject to limitations imposed bythe hop duration, the base slot size and the number of registered remotes. A detailedexplanation of this relationship is provided in Section 2.2.3. Minimum data length anddata transmit delay operate the same as with the base station.Except for the registration process which occurs only when a remote logs onto thenetwork, the whole procedure is repeated on every frequency hop. Refer to the sectionon Modem Commands for complete details on parameters affecting the transmission ofdata.2.2. Data TransmissionThe WIT2410 supports two network configurations: point-to-point and point-to-multipoint. In a point-to-point network, one radio is set up as the base station and theother radio is set up as a remote. In a point-to-multipoint network, a star topology is usedwith the radio set up as a base station acting as the central communications point and allother radios in the network set up as remotes. In this configuration, all communicationstake place between the base station and any one of the remotes. Remotes cannotcommunicate directly with each other. It should be noted that point-to-point mode is asubset of point-to-multipoint mode and therefore there is no need to specify one mode orthe other.2.2.1. Point-to-PointIn point-to-point mode, unless data transmit delay or minimum data length have been set,the base station will transmit whatever data is in its buffer limited to 208 bytes or aslimited by the base slot size. If the base station has more data than can be sent on onehop, the remaining data will be sent on subsequent hops. In addition to the data, the basestation adds some information to the transmission over the RF link. It adds the address ofthe remote to which it is transmitting, even though in a point-to-point mode there is onlyone remote. It also adds a sequence number to identify the transmission to the remote.This is needed in the case of acknowledging successful transmissions and retransmittingunsuccessful transmissions. Also added is a 24-bit CRC to allow the base to check thereceived transmission for errors. When the remote receives the transmission, it willacknowledge the transmission if it was received without errors. If no acknowledgment isreceived, the base station will retransmit the same data on the next frequency hop.In point-to-point mode, a remote will transmit whatever data is in its buffer up to the limitof its maximum data length. If desired, minimum data length and data transmit delay can
WIT2410 2000- 2005 Cirronet Inc 7M-2410-0000 Rev Falso be set, which force the remote to wait until a certain amount of data is available orthe specified delay is exceeded before transmitting. If the remote has more data than canbe sent on one hop, it will send as much data as possible as a packet, adding its ownaddress, a packet sequence number and 24-bit CRC. These additional bytes aretransparent to the user application if the protocol mode is 00 (which is the default). In theevent a remote has more data to send, the data will be sent on subsequent hops. If thetransmission is received by the base station without errors, the base station willacknowledge the transmission. If the remote does not receive an acknowledgment, it willretransmit the data on the next frequency hop. To the user application, acknowledgmentsand retransmissions all take place behind the scenes without the need for userintervention.The WIT2410 has a point-to-point direct mode which fixes the remote radio’s handle at30H. This mode is recommended for point-to-point applications, especially if the remoteis likely to periodically leave and re-enter the coverage area of the base. See the sectionon Network Commands for details of this mode.2.2.2. Point-to-MultipointIn point-to-multipoint mode, data sent from the user application to the base station mustbe packetized by the user application unless the remote device can distinguish betweentransmissions intended for it and transmissions intended for other remote devices. This isnecessary to identify the remote to which the base station should send data. When theuser packet is received by the remote, if the remote is in transparent mode (protocol mode0), the packetization bytes are stripped by the remote. In this instance the remote hostreceives just data. If the remote is not in transparent mode, the remote host will receivethe appropriate packet header as specified by the remote’s protocol mode. Refer to thesection Protocol Modes for details on the various packet formats.When a remote sends data to a base station in point-to-multipoint mode, the remote hostdoes not need to perform any packetization of the data. Remotes can operate intransparent mode even though the base is operating in a packet mode. The remote willadd address, sequence and CRC bytes as in the point-to-point mode. When the basestation receives the data, the base station will add packetization header bytes according toits protocol mode setting.2.2.3. Handle AssignmentHandles are used to reduce overhead by not sending the unique 24-bit serial number IDof a remote when sending or receiving data. The use of the various protocol modes causesthe base radio to issue CONNECT packets when a new remote registers with the base. Inaddition to indicating the presence of a new remote, the CONNECT packets provide thecurrent relationship between remote serial numbers and handles.
WIT2410 2000- 2005 Cirronet Inc 8M-2410-0000 Rev FWhen a remote links to a base and requests registration, it requests by default that it beassigned handle 30H. This default request can be changed by the Set Default Handlecommand. If that handle is not currently in use by another remote, the base will assignthat handle to the remote. If the requested handle is already in use by another remote, thebase will assign the next higher handle that is available. Thus, if a remote requests handle30H and that handle is already assigned, the base will assign the remote handle 31H ifthat is available. If 31H is already assigned, the base will assign handle 32H is that isavailable and so on.When a remote leaves the coverage area of the base or otherwise loses link, e.g. theremote was turned off or put into sleep mode, the base detects this event when the remotedoes not renew its registration within 255 hops. With the default setting of 10msec perhop, this could be as along as 2.55 seconds. If within this time the remote re-establisheslink with the base, the previous handle assigned to this remote will still be marked activein the base radio. Thus the remote will be assigned a new handle. If the base radio is inone of the protocol modes, a new CONNECT packet will be issued indicating the currenthandle assigned to the remote. The remote is identified by the serial number that iscontained in the CONNECT packet.If the radio is to be used in a point-to-point mode where there is only one base and oneremote, using the point-to-point mode command of the radios will override this handlemechanism and always assign the remote the same handle.2.2.4. TDMA OperationFor applications needing guaranteed bandwidth availability, the TDMA operation of theWIT2410 can meet this requirement. In the WIT2410 TDMA scheme, each remote hasan assigned time slot during which it can transmit. The base station time slot is setindependently of the remote time slots through the Set Base Slot Size command. Thebase station assigns each remote a time slot and informs the remotes of the size of thetime slot. All remote time slots are the same size that is determined by the number ofremotes registered with the base station. The slot size is a dynamic variable that changesas the number of registered remotes changes. The remotes are continually updated withthe time slot size. This approach continually maximizes the data throughput. The basestation divides the amount of time available per hop by the number of registered remotesup to a maximum of 16 times slots per hop. If the number of registered remotes is greaterthan 16, the time slots will be spread across the required number of hops. For networkswith more than 16 possible remotes, the Set Duty Cycle command must be used to specifya duty cycle -- the number of hops over which the time slots must be spread. For 1 to 16remotes, no duty cycle is required; for 17 to 32 remotes a duty cycle of at least ½ isrequired; and for 33 to 62 remotes a duty cycle of ¼ or more is necessary. An addedbenefit of using the power save mode to set a duty cycle is improved average currentconsumption efficiency. Refer to the Status Commands section for details of thiscommand.
WIT2410 2000- 2005 Cirronet Inc 9M-2410-0000 Rev FWhen setting up a network, keep in mind that time slot length, maximum packet size andhop duration are all interrelated. The hop duration parameter will determine the time slotsize and the maximum amount of data that can be transmitted per hop by the remotes.There is a hard limit of the absolute maximum amount of data that can be sent on anygiven hop of 212 bytes regardless of any parameters. (Note that this is different than the208 byte maximum for the base station.) The base station requires 1.7 ms overhead fortuning, the synchronization signal and parameter updating, as well as a guard time of500µs between each remote slot. Thus the amount of time allocated per remote slot isroughly:hop duration – base slot – 1.7ms - ( # of registered remotes-1)·500µs( # of registered remotes)Take for example a network comprised of a base station and 10 remotes. A hop durationof 10 ms is chosen. We decide that the base station needs to be able to send up to 32bytes each hop (equivalent to a capacity for the base of ~ 32 kbps). Counting the 1.7 msoverhead for the base packet and making use of the fact that our RF rate is 460.8 kbps,we determine that the base slot requires approximately:Each remote time slot will be:10 ms – 2.3 ms – (9)·0.5 ms 10From our RF data rate of 460.8kbps we see that it takes 17.36 µs to send a byte of data,so each remote will be able to send up to = 18 bytes of data per hop.Note that the 18 bytes is the actual number of data bytes that can be sent. If the WIT2410is using a protocol mode, the packet overhead does not need to be considered. So in thisexample, the total capacity per remote would be:If we figure a minimum margin of safety for lost packets and retransmissions of about20%, we see that this would be more than sufficient to support 14.4 kbps of continuousdata per remote. It is also useful to remember that the asynchronous data input to theWIT2410 is stripped of its start and stop bits during transmission by the radio, yielding a"bonus" of 10/8 or 25% in additional capacity.The above calculations are provided as a means of estimating the capacity of a multipointWIT2410 network. To determine the precise amount of capacity, you can actually set up = 0.32 ms0.32 ms17.36µs32·8460.8kbps+ 1.7 ms = 2.3 ms18 bytes10 ms= 18 kbps
WIT2410 2000- 2005 Cirronet Inc 10 M-2410-0000 Rev Fthe radio system and then query the maximum data length from one of the remotes incontrol mode to discover its exact setting. Divide this number by the hop duration asabove to get the remote's exact capacity.2.2.5. Full Duplex CommunicationFrom an application perspective, the WIT2410 communicates in full duplex. That is,both the user application and the remote terminal can be transmitting data withoutwaiting for the other to finish. At the radio level, the base station and remotes do notactually transmit at the same time. If they did, the transmissions would collide. Asdiscussed earlier, the base station transmits a synchronization signal at the beginning ofeach hop followed by a packet of data. After the base station transmission, the remoteswill transmit. Each base station and remote transmission may be just part of a completetransmission from the user application or the remote terminal. Thus, from an applicationperspective, the radios are communicating in full duplex mode since the base station willreceive data from a remote before completing a transmission to the remote.2.2.6. Error-free Packet Transmission Using ARQThe radio medium is a hostile environment for data transmission. In a typical office orfactory environment, 1% - 2% of the 2.4GHz frequency band may be unusable at anygiven time at any given station due to noise, interference or multipath fading. Fornarrowband radio systems (and also many spread spectrum radio systems which usedirect sequence spreading), this would imply a loss of contact on average of over 30seconds per hour per station. The WIT2410 overcomes this problem by hopping rapidlythroughout the band in a pseudo-random pattern. If a message fails to get through on aparticular channel, the WIT2410 simply tries again on the next channel. Even if twothirds of the band is unusable, the WIT2410 can still communicate reliably.Data input to the WIT2410 is broken up by the radio into packets. A 24-bit checksum isattached to each packet to verify that it was correctly received. If the packet is receivedcorrectly, the receiving station sends an acknowledgment, or ACK, back to the transmittingstation. If the transmitter doesn't receive an ACK, at the next frequency hop it will attemptto send the packet again. When ARQ is enabled, the transmitting radio will attempt tosend a packet packet attempts limit times before discarding the packet. A value of 00Hdisables ARQ. When it is disabled, any transmission received with errors is discarded. Itis the responsibility of the user application to track missing packets. A second parameter,ARQ Mode, allows the choice between using ARQ to resend unsuccessful transmissionsor always sending a transmission packet attempts limit times regardless of the success orfailure of any given transmission.All of this error detection and correction is transparent to the user application. All theuser application sees is error-free data from the modem. However, if the ARQ mode isdisabled, transmissions with errors are discarded, and missing data detection will be the
WIT2410 2000- 2005 Cirronet Inc 11 M-2410-0000 Rev Fresponsibility of the user application. Refer to the Protocol Commands section forcomplete details.2.3. Modes of Operation2.3.1. Control and Data ModesThe WIT2410 has two modes of operation: Control mode and Data mode. When inControl Mode, the various radio and modem parameters can be modified. When in DataMode, only data can be transmitted. The default mode is Data Mode. There are twoways to enter Control Mode. The first way is to assert the Configure (CFG) pin on themodem. Upon entering Control Mode, the modem will respond with a > prompt. Aftereach command is entered, the modem will again respond with a > prompt. As long as theCFG pin is asserted, data sent to the modem will be interpreted as command data. Oncethe CFG pin is deasserted, the modem will return to Data Mode.The second method for entering Control Mode is to send the escape sequence :wit2410(all lower case) followed by a carriage return. In the default mode, the escape sequence isonly valid immediately after power up or after deassertion of the Sleep pin on themodem. The modem will respond in the same way with a > prompt. To return to DataMode, enter the Exit Modem Control Mode command, z>, or assert and deassert theSleep pin. There are three modes for the escape sequence, controlled by the Set EscapeSequence Mode command, zc:zc = 0 Escape sequence disabledzc = 1 Escape sequence available once at startup (default setting)zc = 2 Escape sequence available at any timeThe zc2 mode setting is useful if the user application has a need to change the modemsettings "on the fly". In this mode the escape sequence is always enabled and may be sentat any time after a pause of at least 20ms. The modem will respond in the same way aswhen in the default mode. It is necessary to issue the Exit Modem Control Modecommand, z>, before resuming data transmission. The escape sequence must beinterpreted as data until the last character is received and as such may be transmitted bythe modem to any listening modems.2.3.2. Sleep ModeTo save power consumption for intermittent transmit applications, the WIT2410 supportsa Sleep Mode. Sleep Mode is entered by asserting the Sleep pin on the modem interface.While in Sleep Mode, the modem consumes less than 50µA. This mode allows the radioto be powered off while the terminal device remains powered. After leaving Sleep Mode,the radio must re-synchronize with the base station and re-register.
WIT2410 2000- 2005 Cirronet Inc 12 M-2410-0000 Rev F2.3.3. Low Power Mode and Duty CyclingTo conserve power, WIT2410 remotes power down the receiver and transmitter betweenhops when not in use. Base stations must remain active all the time to handle anytransmission from any remote. Remotes can save even more power by enabling the dutycycle feature. This feature causes a remote to power down for 2N frequency hops where1/2N is the duty cycle. Rather than attempting to transmit on every frequency hop whendata is in the transmit buffer, a remote will attempt to transmit only every 2N hops.Roughly speaking, this will proportionately reduce the average power consumption whileincreasing average latency. When there are more than 16 remotes being operated, dutycycling must be enabled since a maximum of 16 time slots is available per hop.When a remote radio is powered up but is out of range of a base station, it willcontinuous scan the frequency bands for the presence of a base radio. During thisscanning the radio can consume up to 80mA of current. A low power seek mode isavailable in which the remote radios seek base stations only 50% of the time. This willreduce current consumption by about 50% but will double the time it can take a remote tolink with a base up to 4 seconds.2.3.4. RF Flow Control ModeBecause of slight differences in baud rates between transmitting and receiving hosts,when sending large amounts of data (100’s of KB) in one direction in a point-to-pointapplication, it is possible to overrun the receive buffer of the receiving radio. For examplea nominal 115.2Kbaud at the transmitting radio’s host might really be 115,201 and at thereceiving radio’s host it might be 115,199. This is similar to a situation where thetransmitting radio is sent data at a higher baud rate than the baud rate at which data isreceived by the receiving host. To compensate for the variations in nominal baud rates,the WIT2410 supports an RF flow control mode for point-to-point operation. In thismode, when the receive buffer of the receiving WIT2410 is close to full, the receivingWIT2410 stops acknowledging transmissions. The transmitting radio is set to infiniteretries which invokes the RF flow control mode (See Set Packet Attempts Limit in Section5.3). The receiving radio will not begin acknowledging transmissions from thetransmitting radio until more room in the receive buffer has become available. This willcause data in the transmit buffer of the transmitting radio to back up. If it backs up to thepoint where the transmit buffer fills up, the transmitting radio will deassert CTS stoppingdata from the transmitting radio’s host device. Once room is available in the receivingradio’s buffer, the receiving radio will begin acknowledging transmissions from thetransmitting radio allowing the transmitting radio’s buffer to begin to empty which willcause the transmitting radio to reassert CTS. Either one or both of the radios in a point-to-point installation can be configured for the RF flow control. If this mode is invoked in apoint-to-multipoint installation, communications with all radios will be stopped when anyone radio’s receive buffer becomes full.
WIT2410 2000- 2005 Cirronet Inc 13 M-2410-0000 Rev F2.3.5. Co-Existing with 802.11b NetworksIn some cases, if a WIT2410-based network is located in close proximity to an 802.11bnetwork, the WIT2410-based network can interfere with the 802.11b network. To avoidcausing this interference, the WIT2410 radio supports a selection of hopping patterns thatavoid the various 802.11b direct sequence channels. These limited band hopping patternsallow WIT2410-based networks to be used with 802.11b networks without impacting theperformance of the 802.11b networks. The hopping pattern is selected using the pecommand. Please refer to the section 5.3 Protocol Commands for details.2.3.6. European Union SettingsWhen operating the WIT2410 in France, a limited frequency mode must be selected. pevalues of 5, 6 or 7 may be used. To select the limited frequency band pe = 5, at the >configuration mode prompt enter:pe5<CR>Save this setting by typing:m><CR>The limited frequency operation will take effect immediately and will be saved intomemory for use when power is cycled.Use of the WIT2410 within the European Union is limited to a maximum transmit powerincluding antenna gain of 20dBm. If gain antennas are to be used, the low power settingof the WIT2410 must be selected. This setting sets the transmit power at the antennaconnector to 10dBm. In this setting a maximum of 10dB of antenna gain may be used. Toselect low power mode, at the > configuration mode prompt enter:wp0<CR>To save this parameter in non-volatile memory type:m>
WIT2410 2000- 2005 Cirronet Inc 14 M-2410-0000 Rev F3. PROTOCOL MODESIn point-to-point applications, it is generally desired that the radios operate in atransparent mode. That is, raw unformatted data is sent from the host to the radio and isreceived as raw data from the receiving end. The addressing and error detection andcorrection are still performed by the radios, but it is transparent to the user application.To set up a point-to-point network, one radio has to be set up as a base station. When theradios are powered on, the base station will send out the synchronization signal at thebeginning of each hop. The remote will synchronize with the base and automaticallyrequest registration. Once the remote is registered, the radios can transmit data. Protocolmode operation is available in point-to-point mode if desired.If the base station is to be responsible for directing data to a specific remote in point-to-multipoint mode, the data sent to the base station by the user application must adhere to apacket format. This allows transmissions from the base station to be directed to a specificremote. Data received by a base station from a remote is similarly formatted to identifyto the user application the remote that sent the transmission. The remotes may still usetransparent mode without formatting to send data to the base, if desired. The WIT2410supports 10 protocol formats that are described in detail below. The protocol format isselected through the Set Protocol Mode command.Base and remote radios can use protocol modes to insure that a packet is transmitted tothe base without being broken up over multiple hops. The data length value in the datapacket becomes the effective minimum packet length and maximum packet length for thatpacket. Note that if the remote data length is set to a number of bytes that is longer thanthe number of bytes that can be transmitted by a remote on a single hop, the packet willbe discarded. For the base, this value is set by the Set Base Slot Size command. Forremotes this value is dynamically available through the Get Maximum Data Lengthcommand or may be calculated based on the maximum number of remotes that can everbe registered at one time. See Sections 5.3 and 2.2.3 respectively. Also note that usingprotocol modes effectively disables Data Transmit Delay. This means that a packet willnot be transmitted until the entire packet has been sent to the radio, regardless of theamount of time it takes.If the remote hosts can determine what data is directed to them in point-to-multipointmode, the data can be sent to the base station without using a packet format. In thissituation, broadcast mode is selected at the base station by using the Set Default Handleand selecting 3FH as the default handle. In this mode, the automatic retransmission ofunsuccessful transmissions is disabled. This is required since all of the remote modemswill attempt to acknowledge each base transmission when ARQ is enabled.Transmissions that are received with errors are discarded by the radio. The remotedevices must be able to detect a missing packet and request a retransmission by the basedevice.
WIT2410 2000- 2005 Cirronet Inc 15 M-2410-0000 Rev FProtocol Modes Definitionsmode 00 Transparent mode used for point-to-point networksor multipoint remotes; does not support any packettypes.mode 01 This is the simplest protocol mode supporting Datapackets only. This mode is not recommended forbase radios. No CONNECT or DISCONNECTpackets are supported and no sequence numbers areprovided.packet types supported: Datamode 02 This mode includes notification when remotes areregistered or dropped through CONNECT andDISCONNECT packets that are sent to the userapplication at the base station and at the remote. Nosequence numbers are provided.packet types supported: DataCONNECTDISCONNECTmode 04 This is the packet format used by the WIT2400.This allows legacy software to operate theWIT2410 with a minimum of changes. Notehowever, that since different air data rates are used,WIT2410s and WIT2400s cannot be mixed in anetwork.packet types supported: 2400 data format(addresses must be limited to 1..62) modes 05 – 08 reserved for future use.mode 09 This mode sends the protocol mode 01 packetsduring transmit but receives data transparently.mode 0A This mode sends the protocol mode 02 packetsduring transmit but receives data transparently.mode 0C This mode sends the protocol mode 04 packetduring transmit but receives data transparently. modes 0D – 0F reserved for future use.mode 11 This mode sends data transparently but supportsprotocol mode 1 during reception.
WIT2410 2000- 2005 Cirronet Inc 16 M-2410-0000 Rev Fmode 12 This mode sends data transparently but supportsprotocol mode 2 during reception.mode 14 This mode sends data transparently but supportsprotocol mode 4 during reception.Note on Using Protocol Mode 4An important difference between the WIT2400 and the WIT2410 is the dynamicassignment of time slots and handles in the WIT2410. The WIT2400 required that eachremote be configured with a static address which distinguished one remote from another.In the WIT2410, remotes are distinguished by their factory-assigned serial number. Whenusing protocol Mode 4 in the WIT2410, the static address of the WIT2400 is replacedwith the current handle of the WIT2410. In point-to-multipoint configurations, a remote’shandle is not guaranteed to remain the same if the remote drops link with the base andthen re-establishes link. In a point-to-point system, the point-to-point mode of theWIT2410 can be set to guarantee the remote handle does not change.If protocol Mode 4 is used, the data stream being transmitted from the remotes to the baseshould contain information indicating the remote sending the data as the handle assignedto the remote can change when the link to the base is dropped and re-established.
WIT2410 2000- 2005 Cirronet Inc 17 M-2410-0000 Rev F3.1. Packet FormatsThe byte formats for each packet type are shown in the table below. Packet fields areorganized to fall on byte boundaries. In the case of bit-level fields, most-significant bitsare on the left.WIT2400 packet type (mode 04):Base DATA 0000 0010 00HH HHHH LLLL LLLL <0-208 bytes data> 0000 0011Remote DATA 0000 0010 0000 0000 LLLL LLLL <0-212 bytes data> 0000 0011MRTP (WIT2410) packet types (modes 01-03):Transmit and Receive:Base DATA 1110 1001 00HH HHHH LLLL LLLL <0-208 bytes data>Remote DATA 1110 1001 0000 0000 LLLL LLLL <0-212 bytes data>Receive only:CONNECT 1110 1001 10HH HHHH RRRR TTTT 00NN NNNN <3 byte remoteID>DISCONNECT 1110 1001 11HH HHHH 0111 1111 H: handle number (0-63)L : data length (0-208 for base, 0-212 for remote)N: remote's previous network number (if roamed)R: receive sequence number (from previous cell)T: transmit sequence number (from previous cell)Note that while the packet length can be set to 212, the maximum number of bytestransmitted per hop is limited to the lesser of 212 or the length specified by maximum datalength. Packets with a data length longer than that will be discarded and not sent. See GetMaximum Data Length for more details.3.1.1. Data PacketModes 01 & 02:Base 1110 1001 00HH HHHH LLLL LLLL <0-208 bytes data>Remote 1110 1001 0000 0000 LLLL LLLL <0-212 bytes data>Mode 04 (WIT2400):Base 0000 0010 00HH HHHH LLLL LLLL <0-208 bytes data> 00000011Remote 0000 0010 0000 0000 LLLL LLLL <0-212 bytes data> 00000011H: handle number (0-63)L : data length (0-208 for base, 0-212 for remote)This packet carries user data. The handle number is the handle of the receiving remote.When data is being sent from a remote to the base, no handle number is required. Up to212 bytes (208 for base radios) of user data may be carried per data packet but no morethan is specified by the maximum data length parameter. The radio will not break up apacket over multiple hops. Packets with a data length greater than maximum data length
WIT2410 2000- 2005 Cirronet Inc 18 M-2410-0000 Rev Fwill not be sent and will be discarded. This parameter is variable and depends on thenumber of remotes currently registered.Handle 63 is reserved for broadcast packets from the base to all remotes.Acknowledgment requests are not supported for broadcasts. For this reason, it is a goodidea to send broadcast messages several times to increase the odds of reaching allremotes.3.1.3. Connect Packet1110 1001 10HH HHHH RRRR TTTT 00NN NNNN <3-byte remote ID> (base, receiveonly)H: handle number (0-62)R: receive sequence number (from previous cell)T: transmit sequence number (from previous cell)N: network number of the previous base (if roamed)1110 1001 10HH HHHH RRRR TTTT 00NN NNNN <3-byte base ID> (remote, receiveonly)H: handle number (0-62)R: receive sequence numberT: transmit sequence numberN: network number of baseRemotes must go through an automatic registration process when roaming from one baseto another, after loss of contact, or when acquiring a base signal for the first time afterpower up. The base then assigns the remote a handle value, may or may not assign it adedicated time slice depending on the user settings, and notifies the user application ofthe new remote with a connect packet.The network number of the last base the remote was connected to is given to aid usersoftware in resending orphan packets that may have been sent to the remote's previouscell. If the remote has been powered up for the first time and this is the first basecontacted, the last base ID will be reported as 80H.3.1.4. Disconnect Packet (base only, receive only)1110 1001 11HH HHHH 0111 1111H: handle number (1-62)When a remote goes out of range or roams to another cell, the base issues a disconnectpacket to indicate that the remote is no longer available.
WIT2410 2000- 2005 Cirronet Inc 19 M-2410-0000 Rev F4. MODEM INTERFACEElectrical connection to the WIT2410 is madethrough a 16-pin male header on the modemmodule. The signals are 3.3 volt signals and forman RS-232 style asynchronous serial interface.The table below provides the connector pinout.Pin Signal Type Description1GND -Signal and chassis ground2TXD Input Transmit data. Input for serial data to be transmitted. In Control Modealso used to transmit modem commands to the modem.3RXD Output Receive data. Output for received serial data. In Control Mode, alsocarries receive modem status from the modem.4Input Configuration selector. Used to switch between Control and Data Modes.Normally, CFG will be set for Data Mode. An internal 10K pull-up enablesData Mode if this signal is left unconnected. Control Mode is alsoaccessible by transmitting an escape sequence immediately after wakeup or power up.(0v) 1 = Control Mode(3.3v) 0 = Data Mode5Input Request to send. Gates the flow of receive data from the radio to the useron or off. In normal operation this signal should be asserted. Whennegated, the WIT2410 buffers receive data until RTS is asserted.(0v) 1 = Receive data (RxD) enabled(3.3v) 0 = Receive data (RxD) disabled.6SLEEP Input Sleeps/wakes radio transceiver. In sleep mode all radio functions aredisabled consuming less than 50µA. At wake up, any user programmedconfiguration settings are refreshed from non-volatile memory, clearingany temporary settings that may have been set.(3.3v) 1 = Sleep Radio(0v) 0 = Wake Radio7Output Data carrier detect. For remotes, indicates the remote has successfullyacquired the hopping pattern of the base station.(0v) 1 = Carrier detected (synchronized)(3.3v) 0 = No carrier detected (not synchronized)8Output Clear to send. Used to control transmit flow from the user to the radio.(0v) 1 = Transmit buffer not full, continue transmitting(3.3v) 0 = Transmit buffer full, stop transmitting 9 - - Reserved for future use. Do not connect.10 Input Resets the radio.11-15 - - Reserved for future use. Do not connect.16 VCC -Positive supply. Min 3.3 v, 5.0 v nominal, 10.0 v max.RTSDCDCTSCFGReset
WIT2410 2000- 2005 Cirronet Inc 20 M-2410-0000 Rev F4.1. Interfacing to 5 Volt SystemsThe modem interface signals on the WIT2410 are 3.3 volt signals. To interface to 5 voltsignals, the resistor divider network shown below must be placed between the 5 voltsignal outputs and the WIT2410 signal inputs. The output voltage swing of the WIT24103.3 volt signals is sufficient to drive 5 volt logic inputs.4.2. Evaluation Unit and OEM Module DifferencesThe evaluation unit has an RS-232 transceiver that translates RS-232 level signals to 3.3volt signals for input into the OEM module inside the evaluation unit. A typicalschematic is shown in Appendix 7.5. The OEM module does not have any type of RS-232 transceiver and cannot handle the RS-232 voltages. This allows the OEM module tobe easily integrated into any 3.3 volt system without any logic signal translation. In orderfor the OEM module to function properly several pins need to be driven low or tied toground. Pin 5 (RTS) and pin 6 (SLEEP) need to be pulled to ground on the 16-pin maleheader. If you have the OEM module interfaced to an RS-232 transceiver, RTS and DTRneed to be pulled high on the transceiver side. In the evaluation unit, RTS and DTR arepulled high on the transceiver side so the evaluation unit will work with these signals notconnected.4.3. Three Wire OperationThe WIT2410 can be operated in a three wire configuration using just TxD, RxD andGround. To operate the WIT2410 in this configuration, the Sleep and RTS signals mustbe tied to ground. These signals are pulled up on the WIT2410 module and if leftdisconnected will put the radio into sleep mode and RTS will be deasserted.The WIT2410 does not support software flow control (XON/XOFF). Thus when using athree wire configuration, there is no flow control. The radio configuration and/or theapplication must insure the transmit and receive buffers do not overflow. The WIT2410has a 2048-byte transmit buffer and a 1024-byte receive buffer. For example, the defaultsettings for the base slot size and hop duration are 08H and 90H respectively. The 08Hbase slot size allows the base to send 32 bytes of data per hop. The 90H hop durationprovides a 10ms hop dwell time. These default settings provide a base throughput of2200 Ω4300 ΩFrom 5vOutput To 3.3v Input
WIT2410 2000- 2005 Cirronet Inc 21 M-2410-0000 Rev F40kbps (Since the over the air transmission is synchronous, the 32kbps synchronous overthe air rate is equivalent to 40kbps asynchronous into the radio serial port). If the basetransmits continuously at a higher rate than this, unless the default settings are changed,the transmit buffer will eventually overflow. To allow a higher base throughput, eitherincrease the base slot size or the hop duration or both. A similar analysis needs to beperformed for the remote radios. Refer to Section 2.2.3 TDMA Mode for the remotethroughput calculation.4.4. Power-On Reset RequirementsThe WIT2410 has an internal reset circuit that provides a reset signal to themicroprocessor if the supply voltage to the WIT2410 falls below 2.7 volts. Operation ofthe microprocessor at voltages below this voltage is unspecified and can result incorruption of the program memory. When the radio is first powered on, there is an inrushcurrent in excess of 250mA. The power supply in the host must be capable of sourcingthis current without the voltage falling below 2.7 volts at the radio. Failure of the powersupply to meet this requirement can result in “motorboating” of the radio where theinrush current of the radio pulls the supply voltage below 2.7 volts causing the resetcircuit to fire which resets the radio removing the current requirement. Once the voltagerecovers to a level above 2.7 volts, the reset signal is removed from the radio whichcauses the inrush current which causes the voltage to drop causing the reset circuit to fireand so on.If the host circuitry has a reset circuit that generates a reset signal to the radio anytimethe power supply voltage falls below 2.7 volts, the on-board reset circuit can be disabled.Cirronet recommends leaving the reset circuit enabled unless it causes a problem due to asoft turn-on of the power supply voltage by the host. Please contact Cirronet TechnicalSupport for details on disabling the reset circuit.
WIT2410 2000- 2005 Cirronet Inc 22 M-2410-0000 Rev F5. MODEM COMMANDSThe WIT2410 is configured and controlled through a series of commands. Thesecommands are sent to the modem directly when the modem is in Control Mode when themodem is in Data Mode if the escape sequence is enabled. The command syntax is thesame for either method, a one- or two-letter command followed by one or moreparameters. The modem will respond with a two-byte message that indicates the newmodem parameter value. The commands are loosely grouped into five differentcategories: Serial commands, Network commands, Protocol commands, Statuscommands and Memory commands. Each command is described in detail below. In thedescriptions, brackets ([,]) are used to denote a set of optional arguments. Verticalslashes (|) separate selections. For example, given the string wn[?|0..3f], some legalcommands are wn?, wn0, wn3 and wna. Most commands which set a parameter also havea ? option which causes the modem to respond with the current parameter setting, e.g.,wn? Each modem command must be followed by either a carriage return or a line feed.5.1. Serial CommandsThese commands affect the serial interface between the modem and the host. The defaultsettings are 9600 bps and protocol mode 0.Command Descriptionsd[?|00..FF] Set Data Rate DivisorData Rate Divisor (hex)1200 bps =BF2400 bps =5F9600 bps =1714400 bps =0F19200 bps =0B28800 bps =0738400 bps =0557600 bps =03115200 bps =01230400 bps = 00sp[?|00..14] Set Protocol Mode00 =point-to-point transparent mode01 =basic command and data only02 =command, data and connection notification04 =WIT2400 protocol mode05 – 08 =reserved for future use09 =mode 01 during transmit, transparent receive0A =mode 02 during transmit, transparent receive0C =mode 04 during transmit, transparent receive0D – 10 =reserved for future use11 =transparent transmit, mode 01 during receive12 =transparent transmit, mode 02 during receive14 =transparent transmit, mode 04 during receive
WIT2410 2000- 2005 Cirronet Inc 23 M-2410-0000 Rev FSet Data Rate DivisorSets the serial bit rate between the modem and the host. This command takes effectimmediately and will require adjusting the host serial rate to agree. Nonstandard ratesmay be programmed by entering a data rate divisor computed with the following formula:DIVISOR = (230400/RATE)-1Round all non-integer values down.Set Protocol ModeEnables the base station to operate in a multipoint network. Depending on the userapplication, more or less acknowledgment may be desired by the application. Remotescan operate in transparent mode even though the base station is operating in one of thenontransparent modes.When using a protocol mode, make sure to count in packet overhead when calculatingnetwork performance. Refer to the section on Protocol Modes for details on each format.5.2. Network CommandsNetwork commands are used to set up a WIT2410 network and to set radio addressingand configuration.Command Descriptionwb[?|0|1] Set Transceiver Mode0 = remote (default)1 = base stationwd[?|1-3f] Set Default HandleUsed to override automatic handle assignment by the base station30 = defaultwg[?|0|1] Enable Global Network Mode0 = Link only to hop pattern specified by wn parameter (default)1 = Link to any hop pattern, regardless of wn parameterwl[?|0-ff] Set lockout key allowing network segregation beyond network number0 = defaultwn[?|0-3f] Set Hopping Pattern (Network Number)0 = defaultwp[?|0|1] Set Transmit Power0 = 10mW1 = 100mW (default)wr? Read Receive Signal Strengthwu[?|0|1] Set Point-to-Point Direct Mode0 = Multipoint mode (default)1 = Point-to-point direct modedx[?|0-ff](remote only) Set Range optimization0 = default
WIT2410 2000- 2005 Cirronet Inc 24 M-2410-0000 Rev FSet Transceiver ModeSets modem operation as either base station or remote. Default is remote.Set Default HandleSets handle number between 1 and 62 inclusive for a remote. This handle will overridethe automatic handle assignment by the base station. This command can be used inapplications where it is desired to have specific modems have specific handles. Whenspecified for the base, the default handle determines which remote it will address whentransparent protocol mode is in effect. When 3FH is specified for the base, broadcastmode is entered.Enable Global Network ModeFor networks with multiple base stations, remotes are ordinarily only able to link to onebase station, set by the hopping pattern. Mode 1 enables the global mode that allowsremotes to link to any base station they can hear, acquiring whatever hop pattern isrequired. In this mode a remote can only change base stations once it is no longerregistered with a base station.Set Lockout KeyAllows further network segregation beyond the network number. This feature allowsmultiple co-located networks in which global roaming is enabled. In global roaming, aremote is allowed to link to any base regardless of the network number as long as thelockout key agrees. By using different lockout keys, the bases to which remotes link canbe limited or segregated.Set Hopping PatternThe WIT2410 has 64 preprogrammed hopping patterns (also referred to as networknumbers). By using different hopping patterns, nearby or co-located networks can avoidinterfering with each other’s transmissions. Even if both networks tried to use the samefrequency, on the next hop they would be at different frequencies.Set Transmit PowerThe WIT2410 has two preset transmit power levels, 10mW (10dBm) and 100mW(20dBm). Control of the transmit power is provided through this command. Default is100mW.Read Receive Signal Strength Indicator (RSSI)This command reports the relative signal strength averaged over the last 10 hops. Thiscommand returns a one byte value that is proportional to received signal strength and canrange from 00H to FFH. Typical values range from 30H to 80H where the lower thenumber the lower the received signal strength and the higher the number the higher thereceived signal strength. This is a relative indication and does not directly correspond toa field strength number. This is available only at the remotes as the base station is theonly source that transmits on a regular basis. Plus, in a point-to-multipoint network thebase will receive different signal strengths from each remote.
WIT2410 2000- 2005 Cirronet Inc 25 M-2410-0000 Rev FSet Point-to-Point Direct ModeSets point-to-point mode that is recommended for point-to-point applications, especiallywhere the remote radio is mobile and may leave and re-enter the range of the base. Thismode fixes the remote handle assignment to always be 30H and improves the re-registration process. Must be set in both base and remote radios.Set Range Optimization (remote only)This command applies an adjustment factor to the over-the-air timing of remotes tocompensate for the effects of propagation delay at long ranges. The default setting of00H is suitable for ranges of 0 to 0.8 miles (1287 m), with optimal performance at 0.1miles (162m). Each increment of this parameter adds 0.1 miles (162 m) to the workingrange. Thus the optimal and max ranges are determined by:optimal = 0.1mi + 0.1mi x dx = 0.17km + 0.17km x dxmax = 0.8mi + 0.1mi x dx = 1.33km = 0.17km x dxThe following table presents various values of dx and the associated optimal and max ranges.dxsetting range:min optimal max00H 0mi/0km 0.1mi/0.2km 0.8mi/1.3km01H 0mi/0km 0.2mi/0.3km 0.9mi/1.5km04H 0mi/0km 0.5mi/0.8km 1.2 mi/2.0km06H 0.1mi/0.2km 0.7mi/1.2km 1.4mi/2.3km09H 0.4mi/0.7km 1.0mi/1.6km 1.8 mi/3.0km13H 1.4mi/2.3km 2.0mi/3.3km 2.8mi/4.7km31H 4.4mi/7.3km 5.0mi/8.3km 5.8 mi/9.7km45H 6.4mi/10.7km 7.0mi/11.7km 7.8mi/13.0km64H 9.4mi/15.7km 10.0mi/16.7km 10.8mi/18.0kmC8H 19.3mi/32.3km 20.0mi/33.3km 20.8mi/34.7kmFAH 24.4mi/40.7km 25.0mi/41.7km 25.8mi/43.0km Optimal 'dx' setting for various distances.
WIT2410 2000- 2005 Cirronet Inc 26 M-2410-0000 Rev F5.3. Protocol CommandsThese commands can be used to tune the transceiver for optimum transmission of dataacross the RF link. For most applications, the default values are adequate.Command Descriptionpe[?|0-B] Set Alternative Frequency Band0 = USA operation. (~2400 – 2472MHz) (default)1 = ~2448 – 2474MHz, avoids 11b channels 1 – 6 & 142 = Spain (~2448 – 2474MHz), avoids 11b channels 1 – 6 & 143 = Japan (~2471 – 2497MHz), avoids 11b channels 1 - 104 = Canada (~2452 – 2477MHz), avoids 11b channels 1 – 6 & 145 = ~2400 – 2425MHz, avoids 11b channels 6 - 146 = ~2409 – 2435MHz, avoids 11b channels 8 - 147 = ~2419 – 2445MHz, avoids 11b channels 1 & 10 – 148 = ~2430 – 2455MHz, avoids 11b channels 1, 2 & 12 – 149 = ~2440 – 2465MHz, avoids 11b channels 1 – 4 & 14A = ~2449 – 2475MHz, avoids 11b channels 1 – 6 & 14B = ~2459 – 2485MHz, avoids 11b channels 1 – 7ph[?|00-fe](base only)Set Hop Duration90H = default (=10ms)pk[?|00-d0] Set Minimum Data Length01 = defaultpl?(remote only)Get Maximum Data Length (read only)D4 = default (=212 bytes)pn[?|01-3e](base only) Set Maximum Number of Remotes3e = default (=62 remotes)pr[?|00-ff] Set Packet Attempts Limit10H = defaultFFH = Infinite retry (RF flow control point-to-point only)pt[?|00-ff] Set Data Transmit Delay00H = defaultpv[?|0|1](base only)Set Slot Assignment Mode0 = default (dynamic slot assignment)1 = static slot assignmentpw[?|00-34](base only) Set Base Slot Size08H = default (=32 bytes)px[?|0|1] Set ARQ mode.0 = ARQ enabled (default)1 = ARQ disabled (redundant transmission)Note: Incorrect setting of these parameters may result in reduced throughput or loss of data packets.Set Alternative Frequency BandWhen set to 1, limits the operating RF channel set to the 2448 to 2473MHz frequencyband for compliance with French regulatory standards. When set to 2, sets appropriate
WIT2410 2000- 2005 Cirronet Inc 27 M-2410-0000 Rev Foperation for Spain. When set to 3, sets appropriate operation for Japan. This settingshould be set to 0, for FCC-compliant operation in the US (this is the default). ForCanadian operation, set this parameter to 4.Additional 25 channel bands have been provided to avoid hopping through the various802.11b channels. If the WIT2410 is to be used in close proximity to 802.11b networks,these alternative hopsets can be used to avoid interfering with the 802.11b networks.Set Hop DurationSets the length of time the transceiver spends on each frequency channel. A smallervalue will allow the remote to lock on to the base signal faster at system startup, and willgenerally decrease packet latency. A larger value increases network capacity, due todecreased overhead in channel switching. The hop duration is specified in 69.4µsincrements. The default value of 90H corresponds to a duration of 10ms. The maximumvalue of FEH is 17.627ms. For best results, do not specify a duration of less than 3 ms.This value only needs to be set in the base which broadcasts the parameter to all remotes.However, link time can be reduced if this value is also programmed into the remotes,which use it as a starting value when scanning for the base.Set Minimum Data LengthThis sets the minimum threshold number of bytes required to form a packet in transparentmode. The radio will wait until the data transmit delay elapses before sending a datapacket with less than this number of bytes. Can be used to keep short, intermittenttransmissions contiguous. In packet modes, the length parameter in the data packet willoverride this value (See Section 3.1). This value is subject to the maximum data lengtheven in packet mode. See Get Maximum Data Length below.Get Maximum Data Length (remote only, read only)This parameter indicates the largest number of bytes that a remote will transmit per hop,based on the size of the slot it has been allocated by the base. In general more remotesmean less data can be transmitted per remote. By reading this parameter and dividing bythe hop duration, the remote's data rate capacity can be determined. Attempting to sendprotocol mode packets longer than maximum data length will result in the packet beingdiscarded without being sent. See Section 2.3.3 on the tradeoffs between hop durationand data length.Set Maximum Number of Remotes (base only)This parameter limits the number of remotes that can register with a given base. Thedefault is 62 remotes which is the maximum number of remotes that can be registeredwith a base at one time. This command is useful when used in conjunction with globalroaming for load balancing when base stations are collocated. It is also useful to assure aminimum remote throughput.Set Packet Attempts LimitIf ARQ Mode is set to 0, sets the number of times the radio will attempt to send anunsuccessful transmission before discarding it. If ARQ Mode is set to 1, it is the number
WIT2410 2000- 2005 Cirronet Inc 28 M-2410-0000 Rev Fof times every transmission will be sent, regardless of success or failure of a givenattempt. When this parameter is set to FFH, RF flow control mode is entered fortransmissions from the radio (See Section 2.3.4). This mode can be entered for one orboth radios in a point-to-point system. When used in a point-to-point system the wuparameter should be set to 1. Using this mode in a point-to-multipoint system will stoptransmissions to all radios when any one radio has a full buffer or if the base radioattempts to send data to a remote that has recently (<2.5 seconds) left the range of thebase.Set Data Transmit DelayWhen used in conjunction with the minimum data length parameter, this sets the amountof time from the receipt of a first byte of data from the host until the radio will transmit intransparent mode. Default is 00H which causes transmission to occur without any delay.When a host is sending a group of data that needs to be sent together, setting thisparameter will provide time for the group of data to be sent by the host before the radiotransmits. If the length of data to be sent together is longer than the time slot can send,the data will not be sent together but will be broken up over multiple hops. The length oftime the radio will wait is equal to the specified value times the hop duration.Set Slot Assignment Mode (base station only)Sets whether the base station will assign remote transmit slots dynamically, based on thenumber of remotes currently registered or whether the base station will assign remotetransmit slots statically, based on the maximum number of remotes parameter. If staticslot assignment is selected, make sure maximum number of remotes is correctly set.Otherwise remote transmit performance will suffer as transmit time will be reserved forremotes that may not exist. The dynamic assignment mode will generally be preferred;however, the static assignment mode will result in a static maximum data lengthparameter.Set Base Slot Size (base station only)Sets the amount of time allocated for transmission on each hop for the base station timeslot in 69.4µs increments, corresponding to 4 bytes per unit. Maximum value is 34Hwhich corresponds to 208 bytes. If using a protocol mode, attempting to send a packetwith a length longer than this setting will cause the packet to be discarded.Set ARQ ModeSets ARQ mode when set to 0 which is the default. In this mode the radio will resend anunsuccessful transmission until either successful or packet attempt limit attempts havebeen made. When set to 1 selects redundant transmit mode that will send everytransmission packet attempt limit times regardless of success or failure of any givenattempt. When redundant transmit mode is used, receiving radios will discard allsubsequent retransmissions once the transmission has been successfully received. Thusthe receiving host will receive just one copy of the transmission.
WIT2410 2000- 2005 Cirronet Inc 29 M-2410-0000 Rev F5.4. Status CommandsThese commands deal with general interface aspects of the operation of the WIT2410.Command Descriptionzb[?|0|1] Banner Display Disable0 = disabled1 = enabled (default)zc[?|0..2] Set Escape Sequence Mode0 = disabled1 = once after reset (default)2 = unlimited timeszh? Read factory serial number high byte.zm? Read factory serial number middle byte.zl? Read factory serial number low byte.zp[?|0-4] Set the duty cycle at which the modem will wake up to send and receive data.Duty cycle equals 1/2N where the argument of the command equals N.zq[?|0|1](remote only)Low Power Acquisition Mode Enable0 = Disabled (default)1 = Enabledz> Exit Modem Control ModeBanner Display DisableEnables or disables display of the banner string and revision code automatically at power-up. May be disabled to avoid being mistaken for data by the host.Set Escape Sequence ModeEnables or disables the ability to use the in-data-stream escape sequence method ofaccessing Control Mode by transmitting the string ":wit2410". When this mode is setto 1, the escape sequence only works immediately after reset (this is the default). Whenset to 2, the escape sequence may be used at any time in the data stream when precededby a pause of 20 ms. For backwards compatibility with the WIT2400, the string":wit2400" is also accepted for entering Control Mode. Note that the escape sequencemust be interpreted as data by the radio until the last character is received, and as suchwill be generally be transmitted to a receiving radio station, if any.Read Factory Serial Number High, Middle and Low Bytes.These read only commands return one of the three bytes of the unique factory-set serialnumber, which are also visible in the startup banner.Set Duty CycleAllows reduced power consumption by having a remote wake up only every 2N hops toreceive and transmit. Power consumption is roughly proportional to the duty cycleselected. For example, if N=2, the remote will wake up every fourth hop. Power
WIT2410 2000- 2005 Cirronet Inc 30 M-2410-0000 Rev Fconsumption will be roughly ¼ the consumption as when N=0. This parameter must beset to the appropriate value when more than 16 remotes are in use.Enable Low Power Acquisition Mode. When a remote is searching for a base to acquireand register with, it scans the frequency band very rapidly. This mode consumes about80mA of current during this mode. To reduce the frequency consumption when a remoteis in acquisition mode, a low power acquisition mode is provided. In this mode, theremote only scans the frequency band every other hop. This will reduce the averagecurrent consumption during acquisition to about 40mA. The tradeoff is it can take twiceas long to acquire and register with a base, or up to 4 seconds.5.5. Memory CommandsThe WIT2410 allows the user to store a configuration in nonvolatile memory, which isloaded during the initialization period every time the radio is powered up. Note thatchanges to the serial port baud rate from recalling the factory defaults or recallingmemory will not take effect until DTR is toggled or power to the radio is cycled.Command Descriptionm0 Recall Factory Defaultsm< Recall Memorym> Store Memorym! Display Modified ParametersRecall Factory DefaultsResets the WIT2410 to its factory default state. This is useful for testing purposes or ifthere is a problem in operation of the system and the configuration is suspect. Use theStore Memory command afterwards if you wish the factory default settings to beremembered the next time you cycle power or reset the radio.Recall MemoryUseful for restoring the power-on settings after experimenting with temporary changes todata rate, protocol or network parameters, etc.Store MemoryThis command is necessary after any command to change the data rate, transceiveraddress, or other radio setting that you wish to make permanent.Display Modified ParametersThis command lists all parameter settings that are different from the factory defaultsettings. This will list changed parameters whether or not they have been stored with them> command. Note that issuing this command will cause the radio to lose link with thebase and will cause all remotes to lose link when issued to the base radio.
WIT2410 2000- 2005 Cirronet Inc 31 M-2410-0000 Rev F5.6. Modem Command SummarySerial Commandssd[?|00..ff] Set Data Rate Divisorsp[?|00..14] Set Protocol ModeNetwork Commandswb[?|0|1] Set Transceiver Modewd[?|1..3f] Set Default Handlewl[?|0..ff] Set Lockout Keywn[?|00..3f] Set Hopping Patternwg[?|0|1] Enable Global Network Modeswp[?|0|1] Set Transmit Powerwr? Read Receive Signal Strength (remote only)wu[?|0|1] Set Point-to-Point Direct Modedx[?|0..62] Set Range Optimization (base only)Protocol Commandspe[?|0..4] Set Alternative Frequency Bandph[?|00..fe] Set Hop Duration (base only)pl? Get Maximum Data Length (remote only, read only)pn[?|01..3e] Set Maximum Number of Remotes (base only)pk[?|00..d4] Set Minimum Data Lengthpr[?|00..ff] Set Packet Attempts Limitpt[?|00..ff] Set Data Transmit Delay (remote only)pv[?|0|1] Set Slot Assignment Mode (base only)pw[?|00..34] Set Base Slot Size (base only)px[?|0|1] Set ARQ ModeStatus Commandszb[?|0|1] Banner Display Disablezc[?|0..2] Set Escape Sequence Modezh? Read Factory Serial Number High Bytezm? Read Factory Serial Number Middle Bytezl? Read Factory Serial Number Low Bytezp[?|0..4] Set Duty Cyclezq[?|0|1] Enable Low Power Acquisition (remote only)z> Exit Modem Control ModeMemory Commandsm0 Recall Factory Defaultsm< Recall Memorym> Store Memorym! Display Changed ParametersNote: Brackets ([,]) as used here denote a set of optional arguments. Vertical slashes separate selections.For example, given the string wn[?|00..3f], legal commands would be wn?, wn0, wn3, and wn2a.Most commands which set a parameter also have a ? option which displays the current parameter setting;e.g., wn?.
WIT2410 2000- 2005 Cirronet Inc 32 M-2410-0000 Rev F6. WIT2410 DEVELOPER’S KITThe WIT2410 Developer’s Kit contains two self-contained wireless modems (HN-510s)built around the WIT2410M OEM module. In addition, two WIT2410M OEM modulesare included in the kit. The self-contained units allow developers to get up and runningquickly using standard RS-232 interfaces without having to build a CMOS level serialinterface. In addition, the self-contained modems include status LEDs to provide modemstatus information visually. The built-in battery pack allows the developer to use themodems without being tethered to a power source. This provides a simple way to test therange of the radios. Other than the true RS-232 signals of the serial interface, the self-contained modems operate exactly as the OEM modules.Connection is made to the HN-510s through a standard DB-9 connector. The HN-510sare set up as DCE devices requiring the use of a straight-through cable to connect to DTEdevices. The pinout is provided in Section 7.3. The modems can be used with just athree wire connection. Transmit data, receive data and ground are the three requiredconnections. Note that in this configuration, no flow control is available as the WIT2410does not support software flow control.When the developer’s kit is shipped from the factory, one HN-510 is set up as a basestation and the other is set up as a remote. The interface rate for both modems is set at9600 bps. The default setting for the network key allows the modems to communicatewithout changing any settings. As a quick test, separate the two modems by about 5 feet,plug in the power and turn the modems on. Do not connect the modems to any device.The Carrier Detect (CD) LED on the base station will come on immediately. After a fewseconds, the CD LED on the remote will come on. This indicates that the modems havesynchronized and have established a communications link.An important point to remember is that if the base station is in Sleep mode, nocommunications can take place until (1) the base station is taken out of sleep mode and(2) the remote has synchronized with the base station. As the Sleep signal is brought outon the pin usually occupied by DTR, connecting the base station to a PC serial port withDTR de-asserted will put the modem into sleep mode. Some communications programswill attempt to communicate immediately after asserting DTR. The base station willtransmit this data, but the remote will not be synchronized with the base station and willnot receive the transmission. In this instance, do not connect the Sleep signal to DTR ofthe serial port.
WIT2410 2000- 2005 Cirronet Inc 33 M-2410-0000 Rev F7. WinCOMProvided with the developer’s kit is a configuration program designed especially forCirronet’s wireless industrial transceivers or WIT radios. WinCOM is located on theManuals and Software CD included in the developer’s kit. Install WinCOM bynavigating to the Software Tools directory on the Manuals and Software CD and double-click on wincom2.1.exe follow the installation wizard. Once it has installed, openWinCOM by double-clicking on the WinCOM icon on the desktop.
WIT2410 2000- 2005 Cirronet Inc 34 M-2410-0000 Rev FWinCom’s menu structure is typical of Windows conventions with File, Edit, Options,Tools and Help selections.Under File, Save Settings (Ctrl S) saves the currentWinCom settings to the hard drive, Print (Ctrl P)sends whatever text is in the display field to theprinter and Exit terminates the program.Under Edit, Copy, Paste, Find (search) and SelectAll perform the familiar Windows functionality intypical fashion.The Options menu contains the selections, ShowComm Errors which lists any errors encountered inthe PC UART. Check Comm Ports on Bootup tellsWinCom to verify each available port and liststhem as such in the Com Port drop down field.See the section entitled WinCom Tools for anexplanation of this drop down.The Help menu displays the About screen whichlists the version number, hardware and softwareinformation for the system being used.
WIT2410 2000- 2005 Cirronet Inc 35 M-2410-0000 Rev F7.1. Starting the programWhen started, WinCOM de-asserts and re-asserts the DTR line to the radio which resetsthe radio causing the sign-on banner to be displayed. If the baud rate on the computerdoesn’t match the baud rate of the radio, illegible characters will be displayed. By hittingthe PgUp or PgDn key to change the baud rate, then pressing F1 twice to toggle DTR(resets the radio) and causes a new banner to be displayed. Continue changing baud ratesin this fashion until a legible banner is displayed as shown below.The banner indicates the radio firmware version, whether the radio is operating as a baseor a remote and the unique factory serial number of the radio module. If nothing isdisplayed in the communications window of WinCOM, verify the COM port and baudrate settings, then reset the radio (by hitting F1 twice). Cycling power to the radio alsowill cause the sign on banner to be displayed unless the banner is disabled via the BannerDisplay Disable command (zb0).The COM port and baud rate can be changed using the drop down menus on the bottomright. All the available COM ports will be listed in the menu but will have OK or N/Adesignated. If another program that uses a COM port is open, that COM port will not beavailable for use by WinCOM.The boxes on the lower right of the WinCOM window provide the status of the COMport flow control being used to communicate with the radio. Note that DCD is onlyasserted by radios configured as remotes when they are linked to a base radio. Radiosconfigured as bases always assert DCD even if no remotes are linked. Clicking on theDTR or RTS buttons will change the state of the respective signal line in the COM port.
WIT2410 2000- 2005 Cirronet Inc 36 M-2410-0000 Rev FThe radio is normally in data mode – data that is sent to it from the PC is transmitted overthe wireless connection. When the WinCOM window is active, keys typed on thekeyboard will be sent to the radio and will be transmitted. Unless the “Echo” box ischecked the typed data will not be displayed in the WinCOM window of the sendingradio.To change configuration parameters, the radio must be put into configuration mode byclicking on the Config Mode button on the WinCOM window immediately after openingWinCOM or after cycling power to the radio. Another method is to toggle the DTR bypressing the F1 key twice, which de-asserts then re-asserts DTR, then pressing the F3 key(or Config Mode button).When the radio is in configuration mode, a “>” prompt character is displayed in theWinCom window as shown above. Configuration parameters are sent to the radio byentering them in the WinCom window after the “>” prompt and pressing the Enter key.If an invalid command or value is entered, the radio will respond with “Error” as shownabove Until the command to save the parameters (m>) is issued, the new parameters willonly be valid until power is cycled or DTR is toggled by pressing the F1 key twice.New parameter values that have been issued are saved to non-volatile memory using the“m>” command. Refer to the Memory Commands section for details on this and otherhelpful memory commands.To exit configuration mode from the WinCom screen, use the “z>” command and pressEnter as shown below.The return to the data mode is indicated by an absence of the “>” prompt. Refer to theConfiguration Commands section below for details on all the configurable parameters.
WIT2410 2000- 2005 Cirronet Inc 37 M-2410-0000 Rev FWhen the radio is linked to another radio, a communications test can be run by clickingon the Transmit button or pressing the F6 key. Whatever ASCII string is in the TransmitString window will be transmitted as shown below.If the other radio is sending data, the received data will be displayed in the WinCOMwindow.If the Binary box is checked, all characters received will be displayed subject to thelimitations of Windows. For example, a carriage return will not return the cursor to theleft side of the window but the character corresponding to 0xd value of the carriage returnwill be displayed. Similarly, if the Hex Mode box is checked, all characters are displayedin hexadecimal format.The Clear Screen button deletes all the text in the display window. The Clear CTS andClear DCD buttons reset the respective changes counters to zero.
WIT2410 2000- 2005 Cirronet Inc 38 M-2410-0000 Rev FAfter naming the file and clicking on OK, the Capture Data window opens and shows theamount of data being received. Clicking on Done stops the loading of received data intothe file.7.2. Function KeysAll of the function key shortcuts are described below:F1 Toggles state of DTR (Sleep). State is shown in status line.F2 Toggles state of RTS. State is shown in status line.F3 Transmits “:wit2400”. Used to enter control mode.F5 Toggles local echo. If you are transmitting characters through one modemto another WIT2450, this allows you to see what you are typing.F6 Toggles stream mode. Causes WinCOM to transmit a repeating pattern ofcharacters. Useful for testing.F8 Toggles binary mode. Displays extended ASCII and control characters.Useful for testing.PgUp Sets data rate of PC serial port to next higher value. Value is displayed instatus line. Useful when WinCOM is used to change the WIT2450interface data rate. WinCOM can communicate at new data rate withouthaving to exit and re-enter WinCOM.PgDn Sets data rate of PC serial port to next lower value. Value is displayed instatus line.
WIT2410 2000- 2005 Cirronet Inc 39 M-2410-0000 Rev F7.3. WinCom ToolsThere are seven selections under the Tools menu. The first, Obey CTS is useful when justa three wire connection is made between the radio and the computer. Some PCs let theCTS input line float. If CTS is not asserted, the PC COM port will not send data.Note: Unchecking this selection will have the PC COM portignore the state of CTS and transmit data.When WinCOM’s transmit mode is used, data is sent continuously until the user stops itby clicking on Stop or pressing F6. If the second tool, Single Transmit, is checked,clicking the Transmit button will send the Transmit String a single time. There is no needto click Stop. Clicking on the Transmit button a second time will have the stringtransmitted a second time.The third allows for checking of available Comm Ports and is useful for refreshing thelist.The fourth, Transmit Tools allows for testing of the Transparent, WIT2410/WIT910 orWIT2411 settings. Parameters related to how the transmission will take place can be setincluding Handle, Transmit Period, whether or not a Sequence Number should be added,if the Transmission will be continuous or one time, if the data should be sent in HexFormat and whether or not data can be received. Data is entered into the Data field, thenData Size can be set and clicking Fill loads the data into the Transmit Field.The Packet Builder is an easy way to test the multipoint addressing mode of theWIT241x radio. Since the WIT241x operates in a star configuration in multipoint mode,only the base radio needs to address data to specific remotes. All remotes send data backto the base and do not need to address the data to the base. To send a packet of data to aspecific remote in a multipoint network, enter the handle of the desired remote in theHandle window. Type whatever data to be transmitted in the Data to Transmit window.In the bottom window, you will see the entire packet being built as the data is entered in
WIT2410 2000- 2005 Cirronet Inc 40 M-2410-0000 Rev Fthe windows. When all the data has been entered, click on the Transmit button to send thedata.WinCOM has the ability to perform any function or sequence of functions WinCOM canperform through a script file. A script file is a text file that contains one or morecommands and arguments save with a wcr filename extension. Each command isseparated by a carriage return and linefeed. Configuration commands need to have waitperiods between them. The list of commands and their definitions is below:
WIT2410 2000- 2005 Cirronet Inc 41 M-2410-0000 Rev F7.4. Script Commandscp <arg> Selects the COM port to usebr <arg> Selects the baud rate to usedo Asserts DTRdf De-asserts DTRro Asserts RTSrf De-asserts RTScm Sends configuration escape sequenceoo Obey CTS/RTSof Do not obey CTS/RTSsc <cmd(arg)> Send WIT910 format configuration commandwt <arg> Pause for arg millisecondsAn example script file is shown below:br 115200dfwt 200dowt 200cmwt 200sc m!This script file sets the baud rate of the PC COM that WinCOM is using to 115,200 kbps,de-asserts DTR, waits 200 milliseconds, asserts DTR, waits 200 milliseconds, sends theconfiguration mode escape sequence, waits 200 milliseconds and then sends the m!command to the radio. What this script file does is set the PC COM port baud rate to115.2 kbps, puts the radio in config mode and the issues the command to display all ofthe radio parameters that have been changed from factory default. Note that this scriptfile leaves the radio in config mode. Cycling power or toggling DTR will return the radioto data mode.WinCOM prompts you to select the desired .wcr file. Opening the script file causes it toexecuted immediately.The seventh tool allows the loading of a data file for transmission. Navigate to a file thenclick Open and the file is transmitted immediately.
WIT2410 2000- 2005 Cirronet Inc 42 M-2410-0000 Rev F The Capture File dialog displays with a bar showing loading progression. Once the filehas finished transmitting, the Final Average Throughput and Bytes sent numbers will bedisplayed.Finally, the eighth tool is Save to File which launches a Save As dialog that allows anydata received to be loaded into a file.
WIT2410 2000- 2005 Cirronet Inc 43 M-2410-0000 Rev F7.5. Demonstration ProcedureThe procedure below provides a quick demonstration of the WIT241x.1. Attach a transceiver to each computer, preferably between 5' and 30' apart forconvenience. 2. Start WinCOM running on both computers If you prefer, almost any other serialcommunications program such as Procomm or QModem set for 9600 bps willalso work.3. Turn the radios on and use the function keys to set DTR and RTS to 1 (if you areusing a terminal program other than COM24, these are typically setautomatically). The radio should respond by setting both DSR and CTS to 1, andtransmit a short sign-on message including the firmware version and whether theunit is configured as a base or remote. Watch the states of the hardware controllines on the status bar as you do this. The DCD indicator should be lit on the basestation. After a few seconds, the remote unit will acquire the base station's signaland also assert its DCD signal.4. Access modem control mode for each unit. To access modem control mode, usethe F1 key to toggle DTR to 0 and back to 1 and then press the F3 key, whichsends the ":wit2400" escape sequence. If you are not using COM24, simply turnthe radio off and back on and then type ":wit2400" (must be lower case, nobackspace characters). The transceiver should echo back “>” to indicate that youhave entered modem control mode. Check the remote unit's hopping pattern byentering "wn?" at the prompt. The remote should respond with "0", the defaultsetting. Check that the base station's hopping pattern matches this by entering"wn?" at the base station.5. Exit control mode by entering "z>". Do this for both radios. At this point, youshould be able to type characters into either radio and see them appear at the otherside. If you are using WinCOM, you can press the F6 key to transmit a repeatingtest pattern.6. For a range test, disconnect the remote station from the computer and powersupply. The DCD indicator should remain lit as long as the base station is inrange.. 7. Exit COM24 by pressing the ESC key.
WIT2410 2000- 2005 Cirronet Inc 44 M-2410-0000 Rev F8. TroubleshootingRadio is not responding.Make sure DTR is asserted to bring the radio out of sleep mode. DSR should be on toindicate the radio is ready.Can’t enter modem control mode.Make sure the host data rate is correct. The WIT2410 defaults to 9600 bps asynchronous.Evaluation units do not have external access to the CFG_SEL signal; you must use the:wit2410 power-on escape sequence to access modem control mode. The first characterstyped after the radio wakes up should be the escape sequence. Make sure you type thecolon (:) and enter the letters in lower case; the characters following the colon echo toshow you have typed them correctly. If using the “on-the-fly” escape sequence command,make sure a pause of at least 20ms precedes the escape sequence.Remote never detects carrier.Check that the base station is running, and that the remote is programmed to the samehopping pattern. Also check that the hop duration for base and remote are the same, andthat the remote has a non-zero link margin.Carrier is detected, but no data appears to be received.Make sure that RTS is asserted to enable receive character flow. In a point-to-pointapplication, if a remote is not receiving data, check that the base's default handle is thesame as the remote's. In a multipoint application, check that the remote is not configuredfor protocol mode and that the base is using the correct protocol format and destinationhandle.Radio is interfering with other nearby circuits.It is possible for the RF energy envelope to be rectified by nearby circuits that are notshielded for RFI, manifesting as a lower frequency noise signal. If possible, place theantenna at least 1 foot away from the transceiver module, and 3 feet from other circuitboards and obstructions. Place sensitive circuits in a grounded metal casing to keep outRFI.Sign-on banner or modem control mode prompt is unreadable.If the problem is repeatable, check whether the data rates between host and transceivermatch.Range is extremely limited.This is usually a sign of poor antenna coupling. Check that the antenna is firmlyconnected. If possible, remove any obstructions in the near field of the antenna (~3'radius).Transmitting terminal flashes CTS occasionally.
WIT2410 2000- 2005 Cirronet Inc 45 M-2410-0000 Rev FThis indicates that the transmitter is unable to reliably get its data across. This may bethe result of an interfering signal, but most often is caused by overloading of the network.Adjusting the protocol parameters may increase the network efficiency.Receiving terminal drops characters periodically.Set the number of retries to a high number and send a few characters. Check that thetransmitted data can get through under these conditions. Sometimes this symptom iscaused by an application that is explicitly dependent on the timing of the received datastream. The nature of the packetized RF channel imposes a degree of unpredictability inthe end-to-end transmission delay.Cannot communicate with the OEM module.Make sure DTR and RTS are asserted. DSR should be on to indicate the radio is ready.OEM Module is in an unknown state.Use the m0 command to restore the factory defaults. Note that the serial baud rate must beknown for the module to receive this command.
WIT2410 2000- 2005 Cirronet Inc 46 M-2410-0000 Rev F9. APPENDICES9.1. Technical Specifications9.1.1 Ordering InformationWIT2410M4 OEM Module, Serial connector pins down - StandardWIT2410S4 OEM Module, Serial connector pins up9.1.2. Power SpecificationsVcc Input Range: 3.3v to 10.0vOperating Temperature Range: -30°C to +70°CCurrent Consumption (Max transmit power, 230.4Kbps I/O)Mode Remote Base StationSleep 50µA N/AStandby 20mA N/ATypical Average 50mA 80mAPeak (Tx) 80mA 100mA9.1.3. RF SpecificationsFCC Certification Part 15.247, no license requiredETSI (European) Certification brETSI 300.328, no license requiredRated RF Power +18 dBm (+20 dBm effective radiated)Line-of-site Range approx. 6/10 of a mile w/2dB dipoleFrequency Range 2401 – 2495MHzNumber of Channels 75 US; Canada, France, Spain & Japan: 25Receiver Sensitivity -93dBmChannel Data Rate 460KbpsIF Adjacent Channel Rejection >55dB9.1.4. Mechanical SpecificationsWeight 35gDimensions (including shield) 80.2 x 46.5 x 8.6mm(refer to section 7.6 for mechanical drawing)RF Connector:WIT Huber/Suhner: 85 MMCX 50-0-1Mating Huber/Suhner: 11 MMCX-50-2-3 (straight)Huber/Suhner: 16 MMCX-50-2-2 (rt. angle)Data/Power Connector:WIT Samtec: DIS5-108-51-L-DMating Samtec: CLP-108-02-G-D (PCB mount) Samtec: FFSD-08 (IDC cable)
WIT2410 2000- 2005 Cirronet Inc 47 M-2410-0000 Rev F9.2. Serial Connector PinoutsSignal WIT2410M/S4OEM PinoutHN-510DB9PinoutGND 1 5TXD 2 3RXD 3 2CFG 4-RTS 5 7SLEEP 6 4DCD 7 1CTS 8 8The HN-510 is wired as a DCE device and as such can be connected to DTE devices suchas PCs with a straight-through cable. When connecting a HN-510 to a DTE device, a“null modem” cable is required. To effect a null modem cable, cross-wire TXD andRXD and connect ground. The HN-510 can operate with just these three wiresconnected. However, as the WIT2410 does not support software flow control, there willbe no flow control in this mode. If the DTE device fails to respond, connect DCD fromthe HN-510 to the DTR and RTS inputs to activate the DCE device whenever theWIT2410 asserts carrier.When connecting to the WIT2410M/S4, make sure that all of the inputs (TXD, CFG,RTS and SLEEP) are terminated for proper operation.9.3. Approved AntennasThe WIT2410M/S4 is designed to ensure that no antenna other than the one fitted shallbe used with the device. The integrator must permanently affix the antenna by using anadhesive on the coupling such as Loctite, or ensure the antenna has a unique coupling.The table below lists the antennas which can be purchased directly from Cirronet.Contact Cirronet Technical Support with any questions.Description Gain Part Number Coupling24dB Parabolic Dish 24dB PAR2424 Reverse N18dB Parabolic Dish 18dB PAR2418 Reverse N15dB Yagi Directional 15dB YAGI2415 Reverse N14dB Corner Reflector 14dB CORNER2414 Reverse N12dB Omnidirectional 12dB OMNI2412 Reverse N9dB Omnidirectional 9dB OMNI249 Reverse N9dB Corner Reflector 9dB CORNER249 Reverse N6dB Cironnet Patch 6dB PA2400 Reverse MMCX5dB Mobile Mount 5dB MAG245 Reverse N2dB Cirronet Patch 2dB PA2410 Reverse MMCX2dB Rugged Body Mount 2dB RBM242 Reverse NDipole 2dB RWA249R Reverse SMANote: The WIT2410M4 is thestandard part number and hasthe serial connector pinspointing down allowingconnection to a mother boardwithout using a cable.WIT2410S4 has the serialconnector pins pointing up.
WIT2410 2000- 2005 Cirronet Inc 48 M-2410-0000 Rev F9.4. Technical SupportFor technical support call Cirronet at (678) 684-2000 between the hours of 8:30AMand 5:30PM Eastern Time.
WIT2410 2000- 2005 Cirronet Inc 49 M-2410-0000 Rev F9.5. Reference DesignTXDRTS_3.3VIf using a 5.0V converter use thefollowing circuit for TXD,DTR,RTSDCD_3.3VDCDVCC 3.3VU5MAX3238282513165671012212018911826274131415 21917232224C1+C1-C2+C2-R1OUTBT1OUTT2OUTT3OUTT4OUTT5OUTR1OUTR2OUTR3OUTR2INR3INR1INVCCV+V-FORCEONFORCEOFFINVALID GNDT4INT5INT2INT3INT1INDTR_SLEEP_3.3VD1MBR0520L12CTS_3.3V+C31 uFTXD_3.3VRXDC50.1uF12RXD_3.3VR110k1 2C10.22uF12+C41 uFWIT2410 InterfaceR16.8k12R26.8k12VCC 3.3VOptional pullups to keepRTS and DTR assertedwhen left unconnectedTXD_3.3VTXD_5VCTS+C21 uFR220k1 222004300
WIT2410 2000- 2005 Cirronet Inc 50 M-2410-0000 Rev F9.6.1. Mechanical Drawing – WIT2410M4 (Pins Down)
WIT2410 2000- 2005 Cirronet Inc 51 M-2410-0000 Rev F9.6.2. Mechanical Drawing – WIT2410S4 (Pins Up)
WIT2410 2000- 2005 Cirronet Inc 52 M-2410-0000 Rev F10. WarrantySeller warrants solely to Buyer that the goods delivered hereunder shall be free fromdefects in materials and workmanship, when given normal, proper and intended usage, fortwelve (12) months from the date of delivery to Buyer. Seller agrees to repair or replace atits option and without cost to Buyer all defective goods sold hereunder, provided thatBuyer has given Seller written notice of such warranty claim within such warranty period.All goods returned to Seller for repair or replacement must be sent freight prepaid toSeller’s plant, provided that Buyer first obtain from Seller a Return Goods Authorizationbefore any such return. Seller shall have no obligation to make repairs or replacementswhich are required by normal wear and tear, or which result, in whole or in part, fromcatastrophe, fault or negligence of Buyer, or from improper or unauthorized use of thegoods, or use of the goods in a manner for which they are not designed, or by causesexternal to the goods such as, but not limited to, power failure. No suit or action shall bebrought against Seller more than twelve (12) months after the related cause of action hasoccurred. Buyer has not relied and shall not rely on any oral representation regarding thegoods sold hereunder, and any oral representation shall not bind Seller and shall not be apart of any warranty.THE PROVISIONS OF THE FOREGOING WARRANTY ARE IN LIEU OF ANYOTHER WARRANTY, WHETHER EXPRESS OR IMPLIED, WRITTEN ORORAL (INCLUDING ANY WARRANTY OR MERCHANT ABILITY ORFITNESS FOR A PARTICULAR PURPOSE). SELLER’S LIABILITY ARISINGOUT OF THE MANUFACTURE, SALE OR SUPPLYING OF THE GOODS ORTHEIR USE OR DISPOSITION, WHETHER BASED UPON WARRANTY,CONTRACT, TORT OR OTHERWISE, SHALL NOT EXCEED THE ACTUALPURCHASE PRICE PAID BY BUYER FOR THE GOODS. IN NO EVENTSHALL SELLER BE LIABLE TO BUYER OR ANY OTHER PERSON ORENTITY FOR SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES,INCLUDING, BUT NOT LIMITED TO, LOSS OF PROFITS, LOSS OF DATA ORLOSS OF USE DAMAGES ARISING OUT OF THE MANUFACTURE, SALE ORSUPPLYING OF THE GOODS. THE FOREGOING WARRANTY EXTENDS TOBUYER ONLY AND SHALL NOT BE APPLICABLE TO ANY OTHER PERSONOR ENTITY INCLUDING, WITHOUT LIMITATION, CUSTOMERS OFBUYERS.

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