Hartcran House, 231 Kenton Lane, Harrow, Middlesex, HA3 8RP, England Tel: +44 (0) 20 8909 9595, Fax: +44 (0) 20 8909 2233, www.radiometrix.com CXT/CXR Issue 1, 27 July 2012 Multi channel 25kHz NBFM remote control TX/RX The CXT transmitter and CXR receiver modules offer a multi channel, low power, and reliable remote control data link. This makes the CXT/CXR pair ideally suited to those low power applications where existing wideband modules have insufficient range, or where low cost multichannel operation is needed without compromising on RF specification or regulatory requirement. Figure 1: CXT2 transmitter and CXR2 receiver Features Conforms to EN 300 220-3 and EN 301 489-3 High performance double superhet. PLL synthesizer with TCXO SAW front-end filter Usable range over 1km 16 bit unit address (65535 unique addresses) Momentary and Latched outputs Fully screened. Low profile Re-programmable via RS232 interface Low power requirements Applications Industrial telemetry and telecommand HVAC controls Wireless door entry systems Simple On/Off switching In-building environmental monitoring and control High-end security and fire alarms Heavy vehicle/machinery controls Status reporting and monitoring secure systems Technical Summary Operating frequency: 173.200 - 173.325MHz (UK band) 150.825 - 152.450MHz (Australian Band) 433.875 - 434.650MHz (EU band) 458.525 - 459.1MHz (UK band) Other custom VHF and UHF bands 32 channels @ 25kHz channel spacing Transmit power: +10dBm (10mW) / +20dBm (100mW) Supply range: 3.1 – 15V (TX @ 10mW and RX), 4.1 – 15V (TX @ 100mW) Current consumption: 34mA @ 10mW, 90mA @ 100mW (transmit) and 20mA (receive) Receiver sensitivity: -118dBm (for 12 dB SINAD) Serial configuration by inverted RS232 at 3V CMOS level Radiometrix Ltd CXT/CXR – Multi channel Remote Controller Data Sheet page 1 Easy control functions with CXT and CXR: There are certain user applications where a very simple ‘on/off’ control function is needed (for example: control of floodlights, alarm sounders, machine override shutdown). Normally such applications require a simple microprocessor or dedicated remote control chip to be added to the radio module, incurring extra size, cost and sometimes software overhead. Not anymore. The CXT and CXR module pair (based on either LMT2/LMR2 (UHF version) or LMT1/LMR1 (VHF version)) includes a simple-to-use single function controller/actuator, implemented in the firmware of the radio’s internal processor. This code allows the unit to be used as a very simple remote control product, with either a latched or a momentary output. No external control device is required. Two inputs are provided on the CXT transmitter. Grounding input A sends a coded datastream to the CXR receiver which commands it to latch it’s A output high (+3v). Grounding the transmitter B input sends a datastream which resets the receiver A pin to zero. Also, for the duration of the B transmission, the receiver B output is high. The minimum duration of a B output pulse is 300mS. The CXT transmits whenever either A or B are low, but to function the TXE must also be low (this can be tied low for simplicity, or diode 'or'ed with the A, B inputs to minimise current consumption) The data format uses is a modified biphase format with an average data rate of 600 bits per second. A 42 bit data burst is used (preceded by ample preamble). This incorporates a 16 bit unit address. This is easily modified via the 2400 baud serial communication port (SI pin), which allows both the unit address and the channel number (1 of 32 operating frequencies) to be easily modified. Commands are in an easy to understand ‘ascii text and decimal numbers’ form, simply entered by hand from any terminal program. Once programmed, values are stored in non-volatile memory. Radiometrix Ltd CXT/CXR – Multi channel Remote Controller Data Sheet page 2 Figure 2: Application circuits Radiometrix Ltd CXT/CXR – Multi channel Remote Controller Data Sheet page 3 Figure 3: CXT footprint (top view) Pin description –CXT Pin 1a 2a 3a 4a Name Vcc 0V N_TXE TXD Function 3.1 – 15V power supply Ground Transmit Enable (active low) Link to 4b 1b SI Serial frequency programming / configuration 2b 3b 4b A (in) B (in) T_out Main (latching) input Second (cancel) input Link to 4a 1 Notes: 1. Serial programming is by an inverted, CMOS logic level, 2400 baud RS232 datastream applied to the SI pin. 2. TXE has a 100kΩ pullup to Vcc 3. Do not exceed 3v logic levels on SI, A or B. 4. SI input has pullup (50K) to 3v internal rail. 5. A and B inputs have pullups (50K) to 3v internal rail. (A, B inputs: active low) 6. CX versions can be identified by the presence of C7, on the underside of the LMT series TX board Radiometrix Ltd CXT/CXR – Multi channel Remote Controller Data Sheet page 4 Figure 4: CXR footprint (top view) Pin description –CXR Pin 1a 2a 3a 4a 5a Name Vcc 0V RXE RXD N/C (AF out) Function 3.1 – 15V power supply Ground Receiver Enable (active high) Link to 4b No connection, 700mV p-p audio. DC coupled, approx 0.8v bias. 1b SI Serial frequency programming / configuration 2b 3b 4b 5b A (out) B (out) R_in RSSI Main (latching) output Secondary output Link to 4a DC level between 0.5v and 2.2v. 60dB dynamic range 1 NOTES: 1. Serial programming is by an inverted, CMOS logic level, 2400 baud RS232 datastream applied to the SI pin. 2. Do not exceed 3v logic levels on SI, A or B. 3. SI input has pullup (50K) to 3v internal rail. 4. A and B outputs are 3v cmos, active high. Up to 5mA may be drawn from each 5. CX versions can be identified by the presence of C7, on the underside of the LMR series RX board Radiometrix Ltd CXT/CXR – Multi channel Remote Controller Data Sheet page 5 Condensed specifications Frequency 433MHz EU, 458MHz / 173MHz UK and 151MHz Australian bands EU 433.875 - 434.65MHz UK: 458.525 - 459.1MHz 173.200 - 173.325MHz Australian: 150.825 - 152.450MHz Other custom VHF and UHF bands ±1.5kHz 25kHz 32 (controlled via RS232 interface) Frequency stability Channel spacing Number of channels Operating temperature Spurious radiations -20 ºC to +55 ºC (Storage -30 ºC to +70 ºC) Compliant with ETSI EN 300 220-3 and EN 301 489-3 Transmitter Output power +10dBm (10mW) ±1dB (factory adjustable 1 - 25mW) +20dBm (100mW) ±1dB (factory adjustable 25 - 100mW) ±3kHz 2.5kbps FSK (biphase) data stream DC – 5kHz (3V CMOS compatible) <-37dBm <-45dBm (no output in Standby) Peak deviation Modulation type TX modulation bandwidth Adjacent channel TX power TX spurious Supply Voltage Current Inputs Size Interface User RF Recommended PCB hole size Receiver Sensitivity AF bandwidth (-3dB) image spurii / adjacent channel blocking LO re-radiation Auxiliary outputs Supply Voltage Current Size Interface User RF Recommended PCB hole size Radiometrix Ltd 3.1V – 15V (1-25mW) 4.1 – 15V (25 – 100mW) 35mA @ 10mW (nominal) 65mA @ 50mW (nominal) 100mA @ 100mW (nominal) <9µA standby (TXE high or floating) data (CMOS/TTL compatible) 33 x 23 x 9mm (BiM sized footprint, new pinout) 10 (8) pin 0.1" pitch dual row (5+5 or 4+4) header 2pin 0.1” pitch 1.2mm -115dBm for <0.1% data errors) 4kHz <-60db <-65db - 84dB -60dBm RSSI, audio 3.1V – 15V 20mA receive <1µA standby (RXE low) 46 x 23 x 9mm 10 pin 0.1" pitch dual row (5+5) header 2pin 0.1” pitch 1.2mm CXT/CXR – Multi channel Remote Controller Data Sheet page 6 Programming the CXT and CXR A 2400 baud cmos level ‘inverted RS232 format’ (1 start bit, 8 data, 1or 2 stop bits, no parity) is used. These units employs a sub-set of the programming commands used by standard LMT/LMR modules. In addition, the command AVALUE is used to set the address number. As the SI pin is dedicated to serial communication only, the ‘ENABLESERIALMODE’ command string is NOT required. To successfully program the unit it must be in active state (RXE high, or TXE low), so provision should be made to force the unit into this state while programming (either a jumper, or a third pin on the programming connector, could be used). GOCHAN aa AVALUE bbbbb LOAD aa nnnnn RVALUE rrrr <cr> / Serially select channel aa, where aa is ch0 to ch31 Set value for unit address Set value of N register for channel aa, where aa is Channels 0 to 31 Set value for R register Process entry Clear all buffers aa = a two digit channel number from 00 to 31 nnnnn = synthesizer N register value (up to 65535) rrrr = synthesizer R register value (up to 16383) bbbbb = unit address (up to 65535) CXT = N TX = f RF f Channelspacing = 433.900MHz = 17356 25kHz R= f TCXO f channelspacing = 13MHz , So R=520 25kHz VHF CXT units have 10MHz, not 13MHz reference oscillators: R= f TCXO f channelspacing = 10 MHz , So R=400 (for VHF CXT) 25 kHz f RF − 21.4MHz 433.900MHz − 21.4 = = 16500 f Channelspacing 25kHz CXR = N RX = Note: A pause of at least 50ms must be allowed between command strings (EEPROM programming time). Radiometrix Ltd CXT/CXR – Multi channel Remote Controller Data Sheet page 7 Figure 5: Serial programming interface Radiometrix Ltd CXT/CXR – Multi channel Remote Controller Data Sheet page 8 Antenna requirements Three types of integral antenna are recommended and approved for use with the module: A) Whip This is a wire, rod ,PCB track or combination connected directly to RF pin of the module. Optimum total length is 16.4cm (1/4 wave @ 433MHz). Keep the open circuit (hot) end well away from metal components to prevent serious de-tuning. Whips are ground plane sensitive and will benefit from internal 1/4 wave earthed radial(s) if the product is small and plastic cased B) Helical Wire coil, connected directly to RF pin, open circuit at other end. This antenna is very efficient given it’s small size (20mm x 4mm dia.). The helical is a high Q antenna, trim the wire length or expand the coil for optimum results. The helical de-tunes badly with proximity to other conductive objects. C) Loop A loop of PCB track tuned by a fixed or variable capacitor to ground at the 'hot' end and fed from RF pin at a point 20% from the ground end. Loops have high immunity to proximity detuning. Ultimate performance Easy of design set-up Size Immunity proximity effects Range open ground to similar antenna A whip *** *** * * 500m B helical ** ** *** ** 200 C loop * * ** *** 100 The antenna choice and position directly controls the system range. Keep it clear of other metal in the system, particularly the 'hot' end. The best position by far, is sticking out the top of the product. This is often not desirable for practical/ergonomic reasons thus a compromise may need to be reached. If an internal antenna must be used, try to keep it away from other metal components, particularly large ones like transformers, batteries and PCB tracks/earth plane. The space around the antenna is as important as the antenna itself. 0.5 mm enameled copper wire close wound on 3.2 mm diameter former RF 433 MHz = 24 turns A. Helical antenna Feed point 15% to 25% of total loop length RF-GND track width = 1mm 2 C2 C3 C4 C1 4 to 10 cm inside area RF B. Loop antenna 16.4cm C. Whip antenna wire, rod, PCB-track or a combination of these three RF 433 MHz = 16.4 cm total from RF pin. Figure 6: Antenna types (433MHz version) Radiometrix Ltd CXT/CXR – Multi channel Remote Controller Data Sheet page 9 Ordering Information: Part No. VHF CXT1-173-1 CXR1-173-1 CXT1-151-1 CXR1-151-1 Description Frequency band (MHz) Supply (V) RF power (mW) Transmitter Receiver Transmitter Receiver 173.200 - 173.325 173.200 - 173.325 150.825 - 152.450 150.825 - 152.450 3.1 -15 3.1 -15 4.1 -15 3.1 -15 10 UHF CXT2-433-1 CXR2-433-1 CXT2-458-1 CXR2-458-1 Transmitter Receiver Transmitter Receiver 433.875-434.650 433.875-434.650 458.525 - 459.1 458.525 - 459.1 3.1 -15 3.1 -15 4.1 -15 3.1 -15 10 100 100 Notes: 1. CXT/CXR are available on number of other VHF and UHF frequencies. Other non standard UHF band frequencies are subject to SAW filter availability. Radiometrix Ltd CXT/CXR – Multi channel Remote Controller Data Sheet page 10 APPENDIX: CXT2-433-1 & CXR2-433-1 Application boards Radiometrix Ltd CXT/CXR – Multi channel Remote Controller Data Sheet page 11 Radiometrix Ltd Hartcran House 231 Kenton Lane Harrow, Middlesex HA3 8RP ENGLAND Tel: +44 (0) 20 8909 9595 Fax: +44 (0) 20 8909 2233 [email protected] www.radiometrix.com Copyright notice This product data sheet is the original work and copyrighted property of Radiometrix Ltd. Reproduction in whole or in part must give clear acknowledgement to the copyright owner. Limitation of liability The information furnished by Radiometrix Ltd is believed to be accurate and reliable. Radiometrix Ltd reserves the right to make changes or improvements in the design, specification or manufacture of its subassembly products without notice. Radiometrix Ltd does not assume any liability arising from the application or use of any product or circuit described herein, nor for any infringements of patents or other rights of third parties which may result from the use of its products. This data sheet neither states nor implies warranty of any kind, including fitness for any particular application. These radio devices may be subject to radio interference and may not function as intended if interference is present. We do NOT recommend their use for life critical applications. The Intrastat commodity code for all our modules is: 8542 6000 R&TTE Directive After 7 April 2001 the manufacturer can only place finished product on the market under the provisions of the R&TTE Directive. Equipment within the scope of the R&TTE Directive may demonstrate compliance to the essential requirements specified in Article 3 of the Directive, as appropriate to the particular equipment. Further details are available on The Office of Communications (Ofcom) web site: http://www.ofcom.org.uk/ Information Requests Ofcom Riverside House 2a Southwark Bridge Road London SE1 9HA Tel: +44 (0)300 123 3333 or 020 7981 3040 Fax: +44 (0)20 7981 3333 [email protected] European Communications Office (ECO) Peblingehus Nansensgade 19 DK 1366 Copenhagen Tel. +45 33896300 Fax +45 33896330 [email protected] www.ero.dk