LMR1

EW N Issue 1, 06 March 2008 Radiometrix Hartcran House, 231 Kenton Lane, Harrow, HA3 8RP, England Tel: +44 (0) 20 8909 9595, Fax: +44 (0) 20 8909 2233 LMT1/LMR1 VHF Narrow Band FM Low Cost multi channel radio modules VHF The LMT1 transmitter and LMR1 receiver modules offer a multi channel, low power, and reliable VHF data link. This makes the LMT1/LMR1 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: LMT1 transmitter and LMR1 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) 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: 173.200 - 173.325MHz (UK band) 150.825 - 152.450MHz (Australian Band) Other VHF frequencies available 4 UK allocation channels (32 maximum) Transmit power: +10dBm (10mW) nominal @ 3.1V (Adjustable 1 - 25mW) +20dBm (100mW) nominal @ 4.1V (Adjustable 25 - 100mW) Supply range: 3.1 – 15V (@10mW) transmitter and receiver 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 LMT1/LMR1 Data Sheet page 1 Radiometrix Ltd Radiometrix Ltd LMT1/LMR1 Data Sheet Figure 2: LMT1 block diagram page 2 Figure 3: LMT1 footpint (top view) Pin description – LMT1 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) 4.1V – 15V power supply (100mW) Ground Transmit Enable (active low) DC coupled input for 3V CMOS logic. Rin=47kΩ Not present in LMT1 Parallel Channel select LSB Serial frequency programming / configuration1 Parallel Channel select Parallel Channel select Parallel Channel select MSB Not present in LMT1 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. 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 LMT1/LMR1 Data Sheet page 3 Radiometrix Ltd LMT1/LMR1 Data Sheet Figure 4: LMR1 block diagram page 4 Figure 5: LMR1 footpint (top view) Pin description – LMR1 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 LMT1/LMR1 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) For LMT1 Transmitter: R= N TX f Xtal f channelspacing f RF 173.250MHz = = = 6930 f Channelspacing 25kHz = 10MHz , So R=400 25kHz For LMR1 Receiver: R= f Xtal f channelspacing = 13MHz , So R=520 25kHz N RX = f RF − 21.4MHz 173.250MHz − 21.4 = = 6074 f Channelspacing 25kHz 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 SINGLE command is received, or mode is changed by a GOCHAN, SETPAR or SETSER command. SINGLE mode is intended for frequency agile applications. 3. For UK version (173.200 - 173.325MHz band) the following channel assignment is supplied: CH0: 173.250MHz CH1: 173.275MHz CH2: 173.300MHz CH3: 173.325MHz CH4 - CH7: 173.225MHz (only used for alarm applications) CH8 - CH31: 173.325MHz Radiometrix Ltd LMT1/LMR1 Data Sheet page 6 Condensed specifications Frequency Any frequency in the 173MHz and 151MHz bands In UK band, only 173.250, 173.275, 173.300 and 173.325 MHz are used as standard Other custom variants from 130 - 180MHz on any 2MHz band 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 Inputs Size Interface ±1.5kHz 25kHz (12.5kHz by special order) 16 channels controlled by parallel port or 32 via serial RS232 interface -20 ºC to +70 ºC (Storage -30 ºC to +70 ºC) Compliant with ETSI EN 300 220-3 and EN 301 489-3 +10dBm (10mW) ±1dB nominal (factory adjustable 1 - 25mW) and +20dBm (100mW) ±1dB nominal (factory adjustable 25 - 100mW) ±3kHz (±1.5kHz @ 12.5kHz channel spacing) 30ms from TXE transition FSK (F3D) DC – 5kHz (3V CMOS compatible)