radiometrix ltd usx2 data sheet page 1 features conforms to etsi en 300 220-3 and en 301 489-3 high performance double superhet, 128 channel pll s ynthesizer 100mw rf power output: adjustable via serial comma nd data rates up to 5 kbps for standard module usable range over 500m fully screened. low profile feature-rich interface (rssi, analogue and digital baseband) digital rssi output incorporate a 1200baud modem re-programmable via rs232 interface low power requirements applications wireless handheld terminals heavy vehicle/machine remote controls epos equipment, barcode scanners data loggers industrial telemetry and telecommand in-building environmental monitoring and control high-end security and fire alarms vehicle data up/download technical summary operating frequency: 315mhz (usa), 433mhz (european ) and 458mhz (uk) bands 128 channels controlled via rs232 interface 16 channels selected by parallel interface transmit power: 100mw (+20dbm) nominal. adjustable 0.1 ? 100mw supply range: 3.6 - 15v current consumption: 100ma (at 100mw output) transm it, 25ma receive data bit rate: 5kbps max. (standard module) receiver sensitivity: -118dbm (for 12 db sinad) size: 50 x 30 x 12mm figure 1: USX2-433-5 usx2 is small multi-channel half duplex uhf transceiver available for operation on 315mhz, 433mhz and 458mhz bands with the user programmable rf power output of up to 100mw. usx2 offers up to 128 frequency channels in 25khz channel spacing. usx2 also featu res dual vco which allows nbfm multi - channel uhf transceiver issue 1 , 07 may 200 9 hartcran house, 231 kenton lane, harrow, middlesex, h a3 8rp, england tel: +44 (0) 20 8909 9595, fax: +44 (0) 20 8909 223 3, www.radiometrix.com usx2
radiometrix ltd usx2 data sheet page 2 figure 2: usx2 block diagram
radiometrix ltd usx2 data sheet page 3 figure 3: provisional usx2 footprint (top) pin description notes: 1. no inversion occurs between txd and rxd. however af out is inverted relative to txd. 2. parallel channel selects (p0-p3) and txe are act ive low and have 47k internal pullups to 3v 3. open collector output rxd has a 47 k pullup to 3v. 4. the software incorporates a 1200 baud modem, com patible with that implemented in other radiometrix narrowband units ( i1200 tones and format ). modem operation is selected by serial command. 5. main serial port (p0, p3) operates at 9600 baud. (command set is not the same as tr2m, smx families). the unit is capable of operating in 'bas ic' parallel channel select only mode, or in serial controlled 'expanded' mode 6. transmit power can be set by serial command 7. rssi can be read back as a digital value. (on p3 ) 8. if analogue transmit modulation is needed, then connect a series 1 f cap + 500k trimmer (a multiturn is advised) in the txd circuit. adjust trimmer for 90% of peak deviation (+/- 2.7khz) at mean input le vel. pins normal mode serial mode modem mode 1a rf gnd rf ground 2a rf in/out to the antenna 3a rf gnd rf ground 1 txd dc coupled input for ttl/ cmos logic nc 2 txe transmit enable. low = rx mode. high = tx. (10k pull down) nc 3 gnd (0v) 4 vcc dc supply input (3.6 ?15v) 5 p3 parallel channel select msb serial read back b usy 6 p2 parallel channel select tba mod txd 7 p1 p1 - parallel channel select tba mod rxd 8 p0 p0 - parallel channel select lsb pgm in pgm in 9 rssi dc level between 0.5v and 2.5v. 60db dynamic range 10 rxd open collector output of data slicer nc 11 af out 500mv p-p audio. dc coupled, approx 0.8v bias nc
radiometrix ltd usx2 data sheet page 4 usx2 serial interface details (version 4): preliminary the usx2 user interface is accessed through the fou r parallel pins (p0/serial through p3). it has four operating modes: 1. parallel: frequency of operation is selected as one of 16 (c hans 0-15), by means of a 4 bit inverted value applied to p0-p3. the p0 pin will also respond to a lockserialmode datastream (inverted rs232, 9600 baud), which will cause the radio to enter serial mode. in parallel mode, the ident command string is still decoded, but the unit remains in parallel mode. 2. serial: frequency of operation, radio set up, power output and various other parameters are controlled by command strings sent to p0. pin p3 functions as a ' readback' port while p1,2 are not used in this mode . in this mode, decimal values are used (to simplify direct manual programming via a terminal) commands include : : empty command buffer ? or / read back buffer contents < backspace > delete last character < cr > process buffer parallel return to the basic, parallel mode (and turn modem off) dump read back contents of eeprom (output on p3) modem activate 1200 baud modem # nomodem de-activate 1200 baud modem # defch ccc set default channel (non-volatile) # defpow pp set default tx power (non-voltatile) # chan ccc jump to channel (volatile) power pp select tx power (volatile) rssi single read of rssi (output on p3) short enter short command mode # (the following commands are used to set up the radi o operating characteristics, and should be viewed w ith caution. especially the calpower command, which ini tiates a multiple write operation to the power calibration table ) ndiv nnnnn force n divider value (volatile) rdiv rrrrr force r divider value (volatile) rload rrrrr set r divider value # offset ooooo set rx offset # load aa nnnnn set n values for first 16 channels # start nnnnn set n value for ch 16 # step i set increment for table # limit ccc set highest permitted channel number # setpow eee set maximum power output (100mw) calpower (etc) (see factory procedures for more details) test generate a 250hz test modulation (only fuctions in tx mode, cancelled by sending a byte) ident readback a single byte, depending on current mode: parallel: p serial s short 1 modem m (channels 0-15 are individually programmed by the load operation. channels 16-127 are a consecutive table, using the start value as a start point (=channel 16) and increasin g the n value by step with each increase in channel number)
radiometrix ltd usx2 data sheet page 5 ccc = a channel number from 00 to 127 aa = a two digit channel number from 00 to 15 nnnnn = synthesizer n register value, (up to 65535) rrrrr = synthesizer r register value, (up to 16383) pp = power setting value (0 - 30) i = table step (increments of n) (0-7) ooooo = receive mode frequency offset eee = power calibration figure n = channel frequency / (13mhz / r) 13mhz / r = 25khz , so r = 520 (usually) receive offset = 21.4mhz / (13mhz / r) , so = 856 ( usually) a pause of at least 50ms must be allowed after oper ations which result in eeprom programming operation s (all except ndiv, rdiv, goto, pset and rssi). this allows the programming cycle to complete. instructions marked ' # ' output a three byte ' ok< cr> ' sequence after sucessfully completing their e eprom programming cycles when first powered up, the unit will operate on cha nnel and output level specified by the last chan an d power instructions, irrespective of previous ndiv, rdiv, chan or pset operations) 3. short: a limited range of radio functions are controlled by sending a single byte to po 0 - 127 select channel (volatile) 128 - 159 select power ( = byte -128) (volatil e) 200 single read of rssi (output on p3) 201 single byte read, as for ident command 222 reception of 16 consecutive 222 bytes returns radio to serial mode. this mode of operation is intended to provide a simple, fast, serial command mode. 4. modem: commands are interpreted as in serial mode (and 'sh ort' mode may be selected.) in this mode the unit operates as a simple 1200 baud packet modem, with txd (in) on p2 and rxd (out) on p1. the n_txe pin does not control tx switching in this mode, but rather the presence of valid data in the tx buffer initiates a transmit burst. no handshaking i s provided, and the unit has a sufficient over-link data rate to transparently 'stream' continuous data. error co rrection, re-transmission of corrupt packets and ad dressing are not provided. this mode is compatible with other radiometrix 'i 1200' mode equipment, including the narrow band eva l kit. notes: unlike in the rlc and tlc units, the lockserialmode (and fast) commands are non-volatile. once a serial mode is selected, the unit will power up in this mode until a parallel command is received. the command interpreter is case sensitive. use uppe r case. spaces are optional (they are not decoded), provide d the command line does not exceed 16 characters. when manually programming this unit we recommend se tting your terminal to local echo. the 'backspace' key functions normally. all serial communications use 9600baud 'inverted rs 232' 8 bit data, no parity, 1 start bit, 1 or 2 st op bits a simple 'driver' program will be made available to simplify programming of these units, if desired. rssi read operations only function correctly if the unit is in rx mode (n_txe pin is high or floating)
radiometrix ltd usx2 data sheet page 6 condensed specifications (all details are provisional) frequency 315 - 315.375mhz (us band) 433.875 - 434.650mhz (433 mhz eu band) 458.525 - 459.1mhz (458mhz uk band) frequency stability 1.5khz channel spacing 25khz number of channels 128 channels selected via serial rs232 interface first 16 are individually programmable next 112 are a sequential table 16 channels selected via parallel interface supply voltage 3.6 -15v current 45ma transmit (at 10mw output) 100ma transmit (at 100mw output) 25ma receive (or modem ?idle?) operating temperature -20 to +70 c (storage -30 to +70 c) size 50x 30 x 12 mm spurious radiations compliant with etsi en 300 220- 3 and en 301 489-3 interface user 11 pin 0.1" pitch molex rf 3 pin 0.1" pitch molex reprogram 5 pin 0.1" pitch socket in top of case recommended pcb hole size 1.2mm (min.) transmitter output power 100mw (+20dbm); adjustable via serial command 0.1 - 100mw tx on switching time <50 ms modulation type fm, fsk (f1d, f3d) tx modulation bandwidth dc ? 3khz deviation 3khz adjacent channel tx power -37dbm tx spurii <-40dbm inputs data (cmos/ttl compatible) receiver sensitivity -118dbm for 12db sinad image / spurious -60db blocking -84db adjacent channel -60db outputs rssi, audio, data notes : 1. the data slicer cannot be depended upon for d ata waveform frequencies below 250hz 2. when rx is on and a transmitter keys up, again a 50ms period is required to stabilise data output mark/space. i.e. allow at least 50ms of preamble
radiometrix ltd usx2 data sheet page 7 rx received signal strength indicator (rssi) the usx2 has wide range rssi that measures the stre ngth of an incoming signal over a range of 60db or more. this allows assessment of link quality and av ailable margin and is useful when performing range tests. the output on pin 9 of the module has a standing dc bias of up to 0.5v with no signal, rising to 2.5v at maximum indication (rf input levels of -40dbm and a bove). ? vmin-max is typically 2v and is largely independent of standing bias variations. output imp edance is 4.7k . the pin has a 1nf cap to ground. digital rssi output in serial mode, rssi can be read back as a digital value on pin p3. the rssi read back command initiat es a read of the analogue rssi value (as present on pin 9) by an internal 8 bit a/d converter. this converter uses the 3.0v rail as it's reference (so an rssi voltage of 3v will give a read back of 255, while a voltage of 0v will read back 00). practically, the rssi circuit produces about 0.5 - 2.5v (read back value 40 - 212) and this voltage is related (approximately) to the receiver input level by the graph below. 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 -140 -130 -120 -110 -100 -90 -80 -70 -60 -50 -40 rf level (dbm) rssi output (v) figure 4: typical rssi level with respect to receiv ed rf level at usx2 antenna pin the table below relate the receiver input level to the typical analogue voltage output at pin 9 and th e corresponding digital rssi value read back at pin 3 (in serial mode). rf power (dbm) analogue rssi (v) at pin 9 digital rssi value (on pin 3) no signal 0.45 36 (24h) -120 0.65 53 (35h) -110 0.85 75 (4bh) -100 1.2 101 (65h) -90 1.4 123 (7bh) -80 1.65 141 (8dh) -70 1.95 166 (a6h) -60 2.2 187 (bbh) -50 2.3 198 (c6h) -40 2.35 200 (c8h) please note, the rssi graph and the table values ab ove are for indicative purposes only and is not a guarantee of actual rssi characteristics.
radiometrix ltd usx2 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 conn ected 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-tu ning. whips are ground plane sensitive and will benefit from internal 1/4 wave e arthed radial(s) if the product is small and plastic cased b) helical wire coil, connected directly to rf pin, open circu it 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 c apacitor to ground at the 'hot' end and fed from rf pin at a point 20% from the ground end. loo ps have high immunity to proximity de- tuning. the antenna choice and position directly controls t he system range. keep it clear of other metal in th e system, particularly the 'hot' end. the best positi on 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 othe r metal components, particularly large ones like transformers, batteries and pcb tracks/earth plane. the space around the antenna is as important as th e antenna itself. a. helical antenna b. loop antenna rf c1 c2 c4 c3 rf-gnd c. whip antenna 16.4cm rf 0.5 mm enameled copper wire close wound on 3.2 mm diameter former 433 mhz = 24 turns feed point 15% to 25% of total loop length track width = 1mm 4 to 10 cm inside area wire, rod, pcb-track or a combination of these three 433 mhz = 16.4 cm total from rf pin. 2 rf figure 5: antenna types
radiometrix ltd hartcran house 231 kenton lane harrow, middlesex ha3 8rp england tel: +44 (0) 20 8909 9595 fax: +44 (0) 20 8909 2233 sales@radiometrix.com www.radiometrix.com copyright notice this product data sheet is the original work and co pyrighted 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 bel ieved 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 lt d does not assume any liability arising from the application or use of any product or circuit descri bed herein, nor for any infringements of patents or other rights of third parties which may result from the u se of its products. this data sheet neither states nor implies warranty of any kind, including fitness for any particular application. these radio devices ma y 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 th e particular equipment. further details are available on the office of comm unications (ofcom) web site: http://stakeholders.ofcom.org.uk/spectrum/technical /rtte/ information requests ofcom riverside house 2a southwark bridge road london se1 9ha tel: +44 (0)20 7981 3000 fax: +44 (0)20 7981 3333 www.ofcom.org.uk european radiocommunications office (ero) peblingehus nansensgade 19 dk 1366 copenhagen tel. +45 33896300 fax +45 33896330 ero@ero.dk www.ero.dk
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