LMR2

EW N Radiometrix Hartcran House, 231 Kenton Lane, Harrow, HA3 8RP, England Tel: +44 (0) 20 8909 9595, Fax: +44 (0) 20 8909 2233 Issue 2, 01 November 2007 LMT2/LMR2 UHF Narrow Band FM Low Cost multi channel radio modules UHF The LMT2 transmitter and LMR2 receiver modules offer a multi channel, low power, and reliable data link. This makes the LMT2/LMR2 pair ideally suited to those low power applications where existing wideband modules have insufficient range, or where low cost multi-channel operation is needed without compromising on RF specification or regulatory requirement. Figure 1: LMT2 transmitter and LMR2 receiver Features • • • • • • • • • • Conforms to EN 300 220-3 and EN 301 489-3 High performance double superhet. PLL synthesizer with TCXO quasi-dc (peak sampling) data recovery circuit (for enhanced performance on unbalanced datastreams) SAW front-end filter Data rates up to 5 kbps for standard module Usable range over 1km Fully screened. Low profile Feature-rich interface (RSSI, analogue and digital baseband) Re-programmable via RS232 interface Low power requirements Applications • • • • • • • • • Handheld terminals EPOS equipment, barcode scanners Data loggers Industrial telemetry and telecommand In-building environmental monitoring and control High-end security and fire alarms DGPS systems Vehicle data up/download Heavy vehicle/machinery controls Technical Summary • • • • • • • • • Operating frequency: 433.875-434.650MHz (EU band) 458.525 - 459.1MHz (UK band) Other custom UHF bands 32 channels 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) Data bit rate: 5kbps max. (standard module) Receiver sensitivity: -118dBm (for 12 dB SINAD) Serial configuration by inverted RS232 at 3V CMOS level LMT2/LMR2 Data Sheet page 1 Radiometrix Ltd Radiometrix Ltd LMT2/LMR2 Data Sheet Figure 2: LMT2 block diagram page 2 Figure 3: LMT2 footpint (top view) Pin description – LMT2 Pin 1a 2a 3a 4a 5a 1b 2b 3b 4b 5b Name Vcc 0V TXE TXD No pin P0/PGM P1 P2 P3 No pin Function 3.1 – 15V power supply (@ 10mW) 4.1 – 15V power supply (@ 100mW) Ground Transmit Enable (active low) DC coupled input for 3V CMOS logic. Rin=47kΩ Not present in LMT2 Parallel Channel select LSB Serial frequency programming / configuration1 Parallel Channel select Parallel Channel select Parallel Channel select MSB Not present in LMT2 Notes: 1. Serial programming is by an inverted, CMOS logic level, 2400 baud RS232 datastream applied to the P0 pin. 2. Channel select inputs have pullups (50kΩ) to 3v internal rail. Do not exceed 3V logic levels on this port. 3. Channel select inputs are active low 4. TXE has a 100kΩ pullup to Vcc 5. All pins are on an 0.1" grid 6. The pins 5a/b are not present, but are included in footprint for compatibility with other units in this family 7. In the 'off' state a PIN switch open circuits the RF output pin. There are no 'off' state spuri. 8. 10mW unit will operate (with marginally reduced specifications and lower (6-8mW) output power) from a 3.0V rail. This must be well regulated and without noise or ripple, as in this state the unit's internal regulator no longer operates, and provides no supply rejection. 9. 100mW versions should not be run continuously from supply voltages > 9v Radiometrix Ltd LMT2/LMR2 Data Sheet page 3 Radiometrix Ltd LMT2/LMR2 Data Sheet Figure 4: LMR2 block diagram page 4 Figure 5: LMR2 footpint (top view) Pin description – LMR2 Pin 1a 2a 3a 4a 5a 1b 2b 3b 4b 5b Name Vcc 0V RXE RXD AF out P0/PGM P1 P2 P3 RSSI Function 3.1 – 15V power supply Ground Receiver Enable (active high) Data out (open collector, no pullup) 700mV p-p audio. DC coupled, approx 0.8v bias.` Parallel Channel select LSB Serial frequency programming / configuration1 Parallel Channel select Parallel Channel select Parallel Channel select MSB DC level between 0.5v and 2.2v. 60dB dynamic range NOTES: 1. Serial programming is by an inverted, cmos logic level, 2400 baud RS232 datastream applied to the P0 pin. 2. Channel select inputs have pullups (50kΩ) to 3v internal rail. Do not exceed 3v logic levels on this port. 3. Channel select inputs are active low 4. All pins are on an 0.1" grid 5. Data recovery circuit used for RXD is not a simple 'average and compare' type. It is a peak sampling quasi-DC coupled design, allowing a greater than usual flexibility in data format. 6. Unit will operate (with marginally reduced specifications) from a 3.0v rail. This must be well regulated and without noise or ripple, as in this state the unit's internal regulator no longer operates, and provides no supply rejection. Radiometrix Ltd LMT2/LMR2 Data Sheet page 5 Serial interface commands 2400 baud RS232. 8 bit data, no parity, 1 start bit, 1 or 2 stop bits. Serial data is sent to the unit on one of the parallel channel select pins (P0). It is very important that the unit does not 'decode' switch bounce in ordinary operation as a command string, or spurious rewriting of the e2prom will result. For this reason the user must send the 16 character string ENABLESERIALMODE (followed by a carriage return) to activate the serial command mode before sending any of the command strings listed below. Command mode is disabled on power down, or on reception of a # character. To successfully program the unit, it must be enabled ('RXE high (rx) or TXE low (tx)). GOCHAN aa LOAD aa nnnnn SETPAR SETSER RVALUE rrrr SINGLE nnnnn / # Serially select channel aa, where aa is ch0 to ch31 Set value of N register for channel aa, where aa is Channels 0 to 31 Channel selected by 4 bit parallel inputs (ch0 to ch15 only) Channel selected by most recent GOCHAN operation Set value for R register Set value of N for single channel operation. N value NOT stored in EEPROM Process entry Clear all buffers Disable command mode 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) N TX = f RF f Channelspacing = 433.900MHz = 17356 25kHz R= f TCXO f channelspacing = 13MHz , So R=520 25kHz N RX = f RF − 21.4MHz 433.900MHz − 21.4 = = 16500 f Channelspacing 25kHz Note: A pause of at least 50ms must be allowed between command strings (EEPROM programming time). SINGLE mode does not store the N value in EEPROM. Therefore the unit is inoperative after a power down until either another valid SINGLE command is received, or mode is changed by a GOCHAN, SETPAR or SETSER command. SINGLE mode is intended for frequency agile applications. Radiometrix Ltd LMT2/LMR2 Data Sheet page 6 LMT2, LMR2 channels are spaced at 50kHz interval into two frequency groups. 50kHz spacing between sequential channels minimises adjacent channel interference. e.g. 433MHz band Serial or Parallel channel select 0 (P3:P0 = HHHH)* 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 (P3:P0=LLLL)* Frequency (MHz) Serial channel select 16 17 433.950 18 434.000 19 434.050 20 434.100 21 434.150 22 434.200 23 434.250 24 434.300 25 434.350 26 434.400 27 434.450 28 434.500 29 434.550 30 434.600 31 434.650 434.625 434.575 434.525 434.475 434.425 434.375 434.325 434.275 434.225 434.175 434.125 434.075 434.025 433.975 Frequency (MHz) 433.875 433.925 433.900 Note: Parallel select pins: H=3V, L= 0V Radiometrix Ltd LMT2/LMR2 Data Sheet page 7 Condensed specifications Frequency 433MHz EU band, and 458MHz UK band As supplied: EU version: 433.875 - 434.65MHz (25kHz steps) UK version 458.525 - 459.1MHz (25kHz steps) Other custom UHF bands ±1.5kHz 25kHz 16 channels controlled by parallel port or 32 via RS232 interface -10 ºC to +60 ºC (Storage -30 ºC to +70 ºC) Compliant with ETSI EN 300 220-3 and EN 301 489-3 Frequency stability Channel spacing Number of channels Operating temperature Spurious radiations Transmitter Output power Peak deviation TX on switching time Modulation type TX modulation bandwidth Adjacent channel TX power TX spurious Supply Voltage Current +10dBm (10mW) ±1dB (factory adjustable 1 - 25mW) +20dBm (100mW) ±1dB (factory adjustable 25 - 100mW) ±3kHz 30ms from TXE transition FSK (F3D) DC – 5kHz (3V CMOS compatible)