Linx Technologies CMD-KEYX-XXXA Keyfob Transmitter User Manual CMD KEYX xxx Manual 4 27 05

Linx Technologies Keyfob Transmitter CMD KEYX xxx Manual 4 27 05

Users Manual

DESCRIPTIONThe Linx CMD-KEY#-xxx Remote CommandKeyfob is ideal for general-purpose remotecontrol and command applications. This unithas been pre-certified for FCC Part 15,Industry Canada, and CE (433MHz only)compliance, reducing development costs andtime to market. Available in 315, 418, or433.92MHz (418MHz standard), this stylishand compact remote has a range of up to1,000ft when combined with the LR Seriesreceiver. The keyfob can be configured with1 to 5 buttons and the keypad and labelingcan be modified to meet specific customerrequirements. Selectable addressingprovides security and allows the creation ofup to 1024 distinct transmitter-receiverrelationships. The keyfob is available inblack, white, or transparent colors. Thetransmission can be decoded using amatching Linx Function Module, KH Seriesreceiver/decoder, or an LC or LR Seriesreceiver paired with a decoder IC ormicrocontroller. The unit operates from asingle 3V CR-2032 lithium button cell.FEATURESFCC, Canada, and CE pre-certified 1 to 5 buttonsSmall packageCustomizable keypadAPPLICATIONS INCLUDEGeneral Remote Control Keyless EntryGarage / Gate OpenersLighting ControlCall SystemsHome / Industrial AutomationWire EliminationOEM ConfigurationsWith a one-time NRE and minimumorder, Linx can configure the keypadand label areas to meet your specificrequirements. Contact Linx for details.OEM KEYFOB TRANSMITTER DATA GUIDE2.23"1.00"0.45"1.37"S4S2S1 S3S5Revised 4/27/05PART NUMBER DESCRIPTIONCMD-KEY#-xxx-*** Keyfob TransmitterEVAL-xxx-KEY# Keyfob Evaluation System# = Number of Buttons, 1 - 5xxx = 315, 418 (Standard), 433.92 MHz*** = Color Leave blank for standard BlackWHT = White CGY= Gray CBL = BlueCRE = Red CPU = PurpleORDERING INFORMATIONFigure 1: Physical DimensionsWIRELESS MADE SIMPLE
Page 3Page 2THEORY OF OPERATIONThe CMD-KEY#-xxx Keyfob Command Unit combines the LR Series transmitterwith an on-board Holtek HT640 encoder IC to form a simple, yet effective, RFremote-control transmitter. The LR transmitter is a low-cost, high-performancesynthesized ASK/OOK transmitter. The transmitter’s synthesized architecturedelivers outstanding stability and frequency accuracy while minimizing the effectsof antenna port loading and mismatching. This reduces or eliminates frequencypulling, bit contraction, and other negative effects that are common to SAW-based transmitter architectures, providing a significantly higher level ofperformance and reliability.When a button is pressed on the remote unit, power is applied to the internalcircuitry and the encoder IC is enabled. The encoder then detects the logic statesof the address lines and button data lines. These states are formatted into athree-word transmission cycle that continues until the button is released. Theencoder data is used to modulate the transmitter, which, through the antenna,conveys the data into free space. On the receiver side, a decoder IC or custommicrocontroller is used to check the transmitter's address bits against theaddress settings of the receiving device. If a match is confirmed, the decoder’soutputs are set to replicate the transmitter’s button states. These outputs canthen be used to activate external circuitry required by the application.The transmitter is compatible with several Linx receiver products, including theLC, LR, KH, and OEM product families. For applications where range is critical,the LR Series receiver is the best choice due to its outstanding sensitivity. Whenthe keyfob transmitter is combined with an LR Series receiver and the HT658decoder chip, ranges up to 1000 feet are possible. Applications operating overshorter distances will also benefit from the increased link reliability and superiornoise immunity provided by the LR Series receiver.SETTING THE TRANSMITTER ADDRESSThe keyfob allows the selection of oneof 1024 unique addresses. All keyfobsare supplied set to the same address.To avoid contention with other units orto create unique relationships, theaddress can be changed. This isaccomplished by cutting the traces witha sharp object, such as an X-Acto knife.The traces are accessed by removingthe rear cover.If the trace is intact, the address line isconnected to ground, otherwise it isfloating. The receiver's address must match exactly in order for the units tocommunicate. Application Note AN00300 describes in detail how to set theaddress to match any of the receivers offered by Linx. This note can be found inthe Support section of the Linx web site.BUTTON ASSIGNMENTSThe keyfob is available in five unique button configurations. Those configurationsand the corresponding switch numbers are shown in the figure below. The tableshows which encoder data line has been assigned to each switch. When abutton is pressed, the data line will go high, causing the corresponding data lineon the decoder to go high if the addresses match.S4S2S1 S3S5S5S2S5S4S4S2S4S1 S3S2Figure 3: CMD-KEY#-xxx Button AssignmentsFigure 2: DIP Switch AssignmentsButton Data LineS1 D0S2 D1S3 D2S4 D3S5 D4ELECTRICAL SPECIFICATIONSPPaarraammeetteerrDDeessiiggnnaattiioonnMMiinn..TTyyppiiccaallMMaaxx..UUnniittssNNootteessPOWER SUPPLYOperating Voltage VCC 2.1 3.0 3.6 VDC –Supply Current ICC –3.4 –mA –Power-down Current IPDN –5–nA 1TRANSMITTER SECTIONTransmit Frequency Range FCCMD-KEY#-315 –315 –MHz –CMD-KEY#-418 –418 –MHz –CMD-KEY#-433 – 433.92 – MHz –Center Frequency Accuracy –-50 –+50 kHz –ENVIRONMENTALOperating Temperature Range – -40 – +85 °C11. Characterized, but not tested.Notes
Page 5Page 4INSTRUCTION TO THE USERThis device complies with Part 15 of the FCC Rules.Operation of this device is subject to the following two conditions:(1) This device may not cause harmful interference, and(2) this device must accept any interference received, including interferencethat may cause undesired operation.This equipment has been tested and found to comply with the limits for a ClassB digital device, pursuant to Part 15 of the FCC Rules. These limits aredesigned to provide reasonable protection against harmful interference in aresidential installation. This equipment generates, uses and can radiate radiofrequency energy and, if not installed and used in accordance with theinstructions, may cause harmful interference to radio communications.However, there is no guarantee that interference will not occur in a particularinstallation. If this equipment does cause harmful interference to radio ortelevision reception, which can be determined by turning the equipment off andon, the user is encouraged to try to correct the interference by one or more ofthe following measures: Reorient or relocate the receiving antenna. Increase the separation between the equipment and receiver. Connect the equipment into an outlet on a circuit different from that to which thereceiver is connected. Consult the dealer or an experienced radio/TV technician for help. This equipment has been certified to comply with the limits for a Class Bcomputing device, pursuant to FCC Rules. In order to maintain compliance withFCC regulations, shielded cables must be used with this equipment. Operationwith non-approved equipment or unshielded cables is likely to result ininterference to radio and TV reception. The user is cautioned that changes andmodifications made to the equipment without the approval of manufacturercould void the user's authority to operate this equipment. Place the above statement in the instruction manual or insert card.COMPLIANCE REQUIREMENTSThe CMD-KEY#-xxx has been pre-certified by Linx Technologies for FCC Part15 and Industry Canada RSP-100 compliance. The 433.92MHz version has alsobeen tested for CE compliance for use in the European Union. The 315MHz and418MHz versions are not legal for use in Europe.LABELING/INSTRUCTION REQUIREMENTSThe CMD-KEY#-xxx Remote Command Unit has already been labeled inaccordance with FCC, Industry Canada, and CE regulations in effect as of thedate of this document. No further labeling of the unit is needed; however, it isnecessary to include the following statement in the end product’s instructionmanual or insert card.Figure 5: CMD-KEY#-xxx AssemblyCONTENTION CONSIDERATIONSIt is important to understand that only one transmitter at a time can be activatedwithin a reception area. While the transmitted signal consists of encoded digitaldata, only one carrier of any particular frequency can occupy airspace withoutcontention at any given time. If two transmitters are activated in the same areaat the same time, then the signals will interfere with each other and the decoderwill not see a valid transmission, so it will not take any action.BATTERY REPLACEMENTThe remote unit utilizes a standard CR-2032 lithiumbutton cell. In normal use, it will provide 1 to 2 years ofoperation. Access for replacement is accomplished bygently prying apart the two halves of the keyfob at theseam (fingernails will do for this). Once the unit isopen, remove the battery by sliding it out from beneaththe retainer. Replace it with the same type of batterywhile observing the polarity shown in the adjacentfigure.ASSEMBLY DIAGRAMBattery+Figure 4: Battery Access
VCCGNDB1TOUCHPADS5TOUCHPADS4TOUCHPADS3TOUCHPADS2TOUCHPADS1VCCVCCCUT TRACE FOR ADDRESS SELECTGND390kR4GNDHT640U124VCC23D022A921A820A719A618A517A416A315A214A113A012GND11OSC110OSC29TE8DOUT7D76D65D54D43D32D21D1VCCVCCGNDDATA INGNDIADJ/VCCRF OUTGNDVCCPDNTXM-XXX-LRGNDGNDGNDR1Set For FCCCompliancePage 6 Page 7Page 7Figure 7: Schematic DiagramRECEIVERSThere are four options for receivers within the Linxproduct line. The first option is to use one of the OEMFunction Modules, such as the Relay Module or the ACWall Module. These items are also pre-certified andcan be immediately included in a product.The other options are to use one of the Linx receivermodules. The signal sent by the Keyfob transmitter canbe received by the LC Series receiver module or, forlonger range, the LR Series receiver module. Thesemodules can be connected to the Holtek HT658decoder to decode the signal or a custommicrocontroller can be programmed to decode it andtake specific action.The KH Series offers a slightly simpler solution bycombining the LC Series receiver and the HT658decoder in a single package.The basic operation for the system is that when abutton is pressed on the transmitter, a correspondingpin on the decoder will go high (as long as theaddresses match). This can then be connected towhatever circuitry is required by the applicationApplication Note AN00300 discusses in detail how toset the addresses on all of the units. Data guides for allof the receivers, the HT640 encoder, and the HT658decoder can be found on the Linx Technologies website, www.linxtechnologies.com.TYPICAL APPLICATIONSThe outstanding sensitivity of the LRSeries receiver offers the best rangewhen used with the keyfobtransmitter. When using the LRSeries receiver, the Holtek HT658decoder chip should be used todecode the received signal. Thisdecoder has ten address lines thatmust match the keyfob addresslines. A DIP switch is commonlyused to set these, but they can alsobe hardwired. If the address linesmatch, when a button on the keyfobis pressed a corresponding data lineon the decoder (D0-D4) will go high.These data lines can then beconnected to external circuitry toperform whatever function isrequired by the application.FCTN-RLY4-xxxFCTN-WALL-xxxRXM-xxx-LC-SRXM-xxx-LRRXD-xxx-KHGNDR1390kGNDGNDVCCVCCD11D22D33D44D55D66D77VT8DIN9OSC110OSC211GND12A013A114A215A316A417A518A619A720A821A922D023VCC24HT658NC1NC2NC3GND4VCC5PDN6RSSI7DATA8NC9NC10NC11NC12NC13NC14GND15ANT16RXM-XXX-LR-SGNDFigure 6: LR Receiver and HT658 Schematic
LINX TECHNOLOGIES, INC.575 S.E. ASHLEY PLACEGRANTS PASS, OR 97526PHONE: (541) 471-6256FAX: (541) 471-6251www.linxtechnologies.comU.S. CORPORATE HEADQUARTERSLinx Technologies is continually striving to improve the quality and function of its products; forthis reason, we reserve the right to make changes without notice. The information contained inthis Data Sheet is believed to be accurate as of the time of publication. Specifications are basedon representative lot samples. Values may vary from lot to lot and are not guaranteed. LinxTechnologies makes no guarantee, warranty, or representation regarding the suitability orlegality of any product for use in a specific application. None of these devices is intended foruse in applications of a critical nature where the safety of life or property is at risk. The userassumes full liability for the use of product in such applications. Under no conditions will LinxTechnologies be responsible for losses arising from the use or failure of the device in anyapplication, other than the repair, replacement, or refund limited to the original product purchaseprice. Some devices described in this publication are patented. Under no circumstances shallany user be conveyed any license or right to the use or ownership of these patents. DisclaimerWIRELESS MADE SIMPLE© 2005 by Linx Technologies, Inc. The stylizedLinx logo, Linx, and “Wireless Made Simple”are the trademarks of Linx Technologies, Inc. Printed in U.S.A.

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