radiometrix ltd bhx2 data sheet page 1 features conforms to en 300 220-3 and en 301 489-3 any 5mhz band module from 420 - 480mhz available as factory tuned custom variant high performance double superhet, 128 channel pll s ynthesizer with tcxo data rates up to 5 kbps for standard module usable range over 5km fully screened feature-rich interface (rssi, automatic noise squel ch, analogue and digital baseband) incorporates a 1200baud dumb modem user configurable via rs232 interface low power requirements applications 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: 458.5-459.1mhz custom variants from 420mhz to 480mhz on any 5mhz b and 23 channels in 458mhz band (128 channels max.) transmit power: +27dbm (500mw) nominal supply range: 5.5v - 15v current consumption: 350ma transmit, 30ma receive data bit rate: 5kbps max. (standard module) receiver sensitivity: -118dbm (for 12 db sinad) size: 85 x 39 x 13 mm (rf pin version) evaluation platforms : nbek + bhx carrier the bhx2 transceiver module offers a 500mw rf power output in the uk 458mhz band. this makes the bhx2 ideally suited to those low power applications where existing multi-channel narrow band devices like tr2m have insufficient range. figure 1: bhx2-458-5-sma nbfm multi - channel 500mw uhf transceiver hartcran house, 231 kenton lane, harrow, middlesex, ha3 8rp, england tel: +44 (0) 20 8909 9595, fax: +44 (0) 20 8909 223 3, www.radiometrix.com issue 1, 26 july 2012 bhx2
radiometrix ltd bhx2 data sheet page 2 figure 2: bhx2 block diagram
radiometrix ltd bhx2 data sheet page 3 user interface pins name functi on 1 txe transmitter enable. low = on, open = rx mode. inter nal 10k pull-up to 4v 2 txd dc coupled digital data input for 3-12v cmos logic. leave open if unused 3 af in 50mv - 2.5v p-p ac coupled input. variable gain 4 rssi dc level between 0.5v and 2.5v. 60db dynamic range 5 sqf noise operated carrier detect. open collector . on/low = no signal 6 af out 200mv pk - pk audio. dc coupled, approx 1v bias. muted by squelc h 7 rxd open collector output of data slicer suitable for b iphase codes 8 +4.4v out regulated dc supply. 75ma max. drain. p resent if unit is powered 9 0v ground 10 pgm serial programming/configuration input at rs 232 level 11 p1 parallel frequency select inputs. inverted logic, i nternal 10k pullups to 4.4v 12 p2 13 p3 notes: 1. bhx2 transmitter section inverts sense of the b aseband stream, so a logical inversion is present between input of tx and output on rx 2. carrier detect mutes the af and data outputs. it can be disabled by rotating the level set trimmer fully acw. 3. there are no pullups on the open collector outpu ts. 4. the sofware incorporates a 1200baud dumb modem, compatible with that implemented in tx2m, rx2m, tr2m, smx2 and uhx2 radios ( i1200 tone s and format ). 5. rs232 input pins (10 and 11) tolerate true +/- levels. no buffering is required. 6. this unit actually consists of a tr2c rf board a nd an afs2-458 amplifier module, combined with a 5v ldo 7. in future versions of the software, pin 13 will have a modem handshake function 8. the bhx2 has the same footprint/pinout/function as the tr2m (tr2b), but the case is longer, and the rf output is a coaxial connector. c ompared to an tr2m, the minimum supply voltage is higher (5.5v vesus 4.5v). figure 3: bhx2 footprint (top) view
radiometrix ltd bhx2 data sheet page 4 figure 4: bhx2 interfaced to host microcontroller a nd serial port for configuration bhx2 can be directly interfaced to a host microcont roller which can generally be powered by the regulated +4.4v output on pin 8 of bhx2. three i/o pins on the microcontroller port can be assigned to select the first 8 channels on frequenc y table of the appropriate band for which the module is configured by pulling the p1-p3 pins low. channel select pins of bhx2 have internal pull- up to 4v supply rail, hence channel selection opera te on inverted logic. channel p3:p2:p1 458mhz band 0 111 458.525 1 110 458.550 2 101 458.575 3 100 458.600 4 011 458.625 5 010 458.650 6 001 458.675 7 000 458.700 digital received data output (rxd) pin is an open c ollector output, which should be pulled-up to required voltage swing level (e.g. +4.4v or vcc). bhx2 has an automatic noise squelching function whi ch is activated when there is not any rf signal at detectable level on the channel or if the non-coherent noise like interference level is high enough to block any weak rf signal from being recei ved. sqf is provided as an open-collector output for monitoring which should be pulled-up to required voltage swing level. sqf output will jump to pull-up voltage level if received rf signal level at the rf in/out pin of the module is about 3db below the level required to produce 12db sinad level on demodulated af output signal. sqf pin can be connected to an led to act as a carrier detect indicator. pull-up resistor value should be reduced (e.g. 1k ) according to the current requirement to produce s atisfactory brightness on the led used. bhx2 can be configured using any pc/laptop/pda havi ng a serial port and modem/terminal program. txd (pin 3) of db9m connector can be direc tly wired to pgm (pin c10) of the bhx2 and sgn (pin 5) of db9m connector should be either conn ected to common ground or pin c9 of the bhx2. the whole frequency/channel table is user reconfigu rable to 128 channels within 5mhz band of supplied frequency subject to regulatory band limit s. serial channel selection via pgm pin gives access to the whole of regulatory band allocation f or 458.525mhz-458.925mhz (23 channels). txe (mod tx_on) (1) txd (2) af in (3) rssi (4) sqf (5) af out (6) rxd (7) + 4.4v out (8) gnd (9) pgm (10) p1(11) p2 (12) p3 (13) 1k 10k 100nf carrier detect h o s t m i c r o c o n t r o l l e r 1 2 3 txd sgd 4 6 78 9 5 pc serial port adc transmit enable data out data in vdd parallel channel select bhx2
radiometrix ltd bhx2 data sheet page 5 received signal strength 0.5 0.7 0.9 1.1 1.3 1.5 1.7 1.9 2.1 2.3 2.5 -130 -120 -110 -100 -90 -80 -70 -60 -50 -40 rf level (dbm) rssi output (v) figure 5: rssi voltage variation with respect to rf level at bhx2 if the microcontroller has a built-in analogue to d igital converter (adc), the received signal strength indicator (rssi) output voltage level can be read by the microcontroller to estimate its distance from transmitting bhx2 unit or identify ar eas of weak signal reception. rssi can also be used to make a decision to switch to the second antenna in fixed installations within building where the probability of null-spots are higher.
radiometrix ltd bhx2 data sheet page 6 bhx2 serial configuration commands 2400 baud rs232. 8 bit data, no parity, 1 start bit , 1 or 2 stop bits, no flow control single nnnnn set value of n for single channel operation gochan xx serial select of channel xx (0 to 127) loadmx xx set highest permitted (serial selected) channel xx (others default to ch0) load aa nnnnn set value of n for channel aa (cha nnels 0 to 15) loadtb nnnnn set value of n for channel 16 (chan nels 17 to 127 then in sequence) rvalue rrrr enter value for r register setpar channel selected by 3 bit parallel input (0 to 7). disable modem setser channel selected by most recent 'gochan' ope ration setmod enable internal modem. frequency selected by most recent 'gochan' or 'single' offset set receive frequency offset (for 25khz this is 1800) gotest 250hz test tone transmission process entry / clear all buffers xx = channel number from 00 to 127 aa = two digit channel number from 00 to 15 nnnnn = synthesizer n register value, (up to 6553 5) rrrr = synthesizer r register value, (up to 1638 3) 18341 khz 25 mhz 525 . 458 f f n cing channelspa rf = = = khz 25 mhz 13 f f r cing channelspa tcxo = = , so r=520 on receive, the local oscillator operates at 45mhz (the first if) below the carrier. an offset value is subtracted from the channel's n value when the unit is switched into rx offset = first if / fc, so, offset = 45mhz / 25khz = 1800 (usually) notes: 1. a pause of at least 50ms must be allowed between command strings (eeprom programming time) 2. single mode does not store the n value in eeprom . therefore the unit is inoperative after a power down until either another valid singl e command is received, or mode is changed by a gochan, setpar or setser command. sin gle mode is intended for frequency agile applications. 3. /setpar command should be issued at the end of c hannel programming to put the module back into parallel frequency select mode 4. in 458mhz band, channel 12 (458.825mhz) and chan nel 15 (458.900mhz) are allocated specifically for fixed alarm and radio keys/vehicle paging applications respectively and should not be used for general purpose applications . 5. user can modify the frequency table of 128 chann els to any desired frequency by changing n, r values of synthesizer within 2.5mhz of factory set channel 0 frequency subject t o the radio regulatory band allocation in the country of intended use. 6. all other frequency, power, analogue input gain and automatic noise squelching adjustment will be treated as custom variants of the module to be set by factory.
radiometrix ltd bhx2 data sheet page 7 pin description of bhx2 with modem mode selected the 'modem' mentioned is a 1200 baud rs232 semi-int elligent unit (transmit keyed when valid serial data is present, so no separate tx control n eeded. coding in the datastream also permits the receiver to ignore noise and only output valid serial data). this is a half duplex unit, so collisions between transmitted and received packets must be dealt with by the user. pin name function 1 mod tx_on open = normal modem operation. low = co nstant tx (for test). 10k pullup to 4v 2 mod nc leave open 3 mod nc leave open 4 rssi dc level between 0.5v and 2.5v. 60db dynamic range 5 mod nc leave open 6 af out modem tones or noise present 7 nc leave open 8 +4.4v out regulated dc supply. 75ma max. drain. p resent if unit is powered 9 0v ground 10 pgm serial programming/configuration input at rs232 lev el 11 mod txd rs232 data input (true). 10k pullup to 4 v 12 mod rxd inverted rs232 data out (to inverting bu ffer like max232) 13 mod nc leave open bhx2s on both ends should be configured to required operating frequency using gochan command before starting to use the internal 1200 baud modem, because the p1-p3 pins will be used as modem data pins and the modem will operate on the last serially selected channel after setmod command is u sed to enable the modem. txe (mod tx_on) (1) txd (mod nc) (2) af in (mod nc) (3) rssi (4) sqf (mod nc) (5) af out (6) rxd (mod nc) (7) + 4.4v out (8) gnd (9) pgm (10) p1 (mod txd) (11) p2 (mod rxd) (12) p3 (mod nc) (13) 1 2 3 txd rxd sgd 4 67 89 5 serial com port rs232 driver vdd sw1 bhx2 figure 6: bhx2 interfaced to pc serial port in mode m mode note: baud rate used for modem is half that of used for s erial configuration. attached rs232 devices should be set with the following: 1200bps, 8 data bits, no parity, 1/2 stop bits, no flow control txd (pin 3) of a serial port can be switched from p gm (pin c10) to mod txd (pin c11) with no rs232 driver in between. however, mod rxd ( pin c12) requires an rs232 line driver before it can be connected to rxd (pin 2) of a serial port. some of the rs232 line drivers can be powered from the regulated +4.4v out (pin c8).
radiometrix ltd bhx2 data sheet page 8 condensed specifications frequency 458.5-459.1mhz (any 5mhz band from 420-480mhz) and any 3mhz band from 210 ? 270mhz frequency stability +/- 1.5khz channel spacing 25khz (12.5khz by special order) number of channels 128 channels controlled via rs232 interface (8 pa rallel selected) transmit output power +27dbm (500mw) 1db tx on switching time 50 ms modulation type fm, fsk (f1d, f3d) tx modulation bandwidth dc ? 3khz adjacent channel tx power -37dbm inputs analogue, data (cmos/ttl compatible) receive sensitivity -118dbm for 12 db sinad image / spurious -70db blocking -85db adjacent channel <-65db (tested per. etsi en 301 489-3) outputs rssi, carrier detect, audio, data spurious radiations compliant with etsi en 300 220- 3 and en 301 489-3 power on to valid audio 28ms (no noise mute) power on to valid audio 45ms (with noise mute) power on to stable data out (50:50 mark / space) 50ms (with or without mute) supply v oltage 5.5 - 15v (+5v regulated version available) current 350ma nominal transmit 30ma receive interface user 13pin 0.1" pitch molex power 2pin 0.1" pitch molex rf 3pin 0.1" pitch molex or sma (long, bulkhead mounted type) or mcx recommended pcb hole size 1.2mm (min.) size 85 x 39 x 13 mm case only (rf pins version) 92 x 39 x 13mm (including mcx) 105 x 39 x 13mm (including sma) operating temperature -20 to +60 c (storage -30 to +70 c) intended approval etsi radio standard en 300 220-3 and emc standard en 301 489-3 notes : 1.the data slicer cannot be depended upon for dat a 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 ordering information: part no. antenna connector frequency band bhx2-458-5 rf pins 458.5 - 459.1mhz bhx2-458-5-sma sma 458.5 - 459.1mhz bhx2-458-5-mcx mcx 458.5 - 459.1mhz bhx2-xxx-5 where xxx is any 5mhz band from 420-480m hz) and any 3mhz band from 210 ? 270mhz bhx2-xxx-5-sma bhx2-xxx-5-mcx
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 the particula r equipment. further details are available on the office of comm unications (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 information.requests@ofcom.org.uk european communications office (eco) peblingehus nansensgade 19 dk 1366 copenhagen tel. +45 33896300 fax +45 33896330 ero@ero.dk www.ero.dk
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