TR2M

EW N Issue 3, 27 April 2007 Radiometrix Hartcran House, 231 Kenton Lane, Harrow, HA3 8RP, England Tel: +44 (0) 20 8909 9595, Fax: +44 (0) 20 8909 2233 TR2M/TR2I Narrow MultiNarrow Band FM Multi-channel UHF Transceiver The TR2M transceiver module offers a low power, reliable data link in an industry-standard pin out and footprint. This makes the TR2M ideally suited to those low power applications where existing wideband modules have insufficient range, or where multi-channel operation is needed. Two versions are available, covering the 458.5-459.1MHz UK band (at 100mW) and the European 433.05-434.79MHz band (at 10mW). Features Figure 1: TR2I-458-5 transceiver 433MHz version conforms to EN 300 220-3 and EN 301 489-3 458MHz version to MPT 1329 (UK specs). Any 5MHz band module from 420MHz to 480MHz available as factory tuned custom variant High performance double superhet, 128 channel PLL Synthesizer with TCXO Data rates up to 5 kbps for standard module Usable range over 1km (with 100mW variant) Fully screened Feature-rich interface (RSSI, automatic noise squelch, 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 Size: 59 x 38 x 10mm Operating frequency: 458.5-459.1MHz or 433.05-434.79MHz Custom variants from 420MHz to 480MHz on any 5MHz band 23 channels in 458MHz band, 69 channels in 433MHz band (128 channels max.) Transmit power: +20dBm (100mW) nominal Supply range: 4.5V - 16V Current consumption: 110mA transmit, 27mA receive Data bit rate: 5kbps max. (standard module) Receiver sensitivity: -118dBm (for 12 dB SINAD) Radiometrix Ltd TR2M Data Sheet page 1 Radiometrix Ltd TR2M Data Sheet Figure 2: TR2M block diagram page 2 A: A: B: B: B: C: C: C: C: C: C: C: C: C: C: C: C: C: 1 Vcc 2 Gnd 1 RF Gnd 2 RF in 3 RF Gnd 1 TXE (MOD TX_ON) 2 TXD (MOD NC) 3 AF in (MOD NC) 4 RSSI 5 SQF (MOD NC) 6 AF out 7 RXD (MOD NC) 8 +4.4V out 9 0V 10 PGM 11 P1 (MOD TXD) 12 P2 (MOD RXD) 13 P3 (MOD NC) 59mm 3.1mm 2.7mm A 8.9 mm Squelch adj. 38.5mm 33mm 1 Input gain. B 1 53.3mm C Unit height 10mm Figure 3: TR2M Footprint (Top) Pin Description - TR2M Pins A1 A2 B1 B2 B3 C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 C13 Name Vcc GND RF GND RF RF GND TXE (MOD TX_ON) TXD (MOD NC) AF in (MOD NC) RSSI SQF (MOD NC) AF out RXD (MOD NC) +4.4V out 0V PGM P1 (MOD TXD) P2 (MOD RXD) P3 (MOD NC) Function 4.5V-16V Ground RF ground To the antenna RF ground Transmitter Enable. Low = ON, Open = RX mode. Internal 10kΩ pull-up to 4V DC coupled digital data input for 3-12V CMOS logic. Leave open if unused AC coupled Analogue Input Limit to 1Vpk-pk ±10% to keep distortion 2.5kHz DC level between 0.5V and 2.5V. 60dB dynamic range Noise operated carrier detect. Open collector. ON/low = no signal 200mVpk-pk audio. DC coupled, approx 1V bias. Muted by squelch Open collector output of data slicer suitable for Biphase codes Regulated DC supply. 75mA max. drain. Present if unit is powered Ground Serial programming/configuration input at RS232 level Parallel frequency select inputs. Inverted logic, internal 10kΩ pullups to 4V Notes: 1. TR2M receiver section inverts the sense of the baseband stream, so a logical inversion is present between input of TX and output of RX. A version is available (TR2I) which inverts the transmit datastream as well (resulting in no net inversions between a pair of TR2I radios). 2. Carrier detect on TR2M mutes the AF Out and RXD outputs. It can be factory disabled. 3. All the open collector outputs must be connected to Vcc/+4.4V out via a pull-up resistor. 4. The software incorporates a 1200baud dumb modem, compatible with that implemented in TX2M, RX2M radios (I1200 tones and format) 5. With 1200baud modem mode enabled, parallel selection of channel is unavailable as the P1-P3 lines are used for modem input/output operations. 6. PGM and MOD TXD (pin 10 and 11) tolerate true ±RS232 levels. No buffering is required. Radiometrix Ltd TR2M Data Sheet page 3 TXE (MOD TX_ON) (C1) TXD (MOD NC) (C2) AF in (MOD NC) (C3) RSSI (C4) Transmit Enable ADC 1kΩ Carrier Detect Data In 10kΩ 100nF VDD Parallel Channel Select TR2M-433-5 AF out (C6) RXD (MOD NC) (C7) +4.4V out (C8) GND (C9) PGM (C10) P1 (MOD TXD) (C11) P2 (MOD RXD) (C12) P3 (MOD NC) (13) 6 7 8 9 2 3 4 5 TXD SGD Figure 4: TR2M interfaced to host microcontroller and serial port for configuration TR2M can be directly interfaced to a host microcontroller which can generally be powered by the regulated +4.4V output on pin 8 of TR2M. Three I/O pins on the microcontroller port can be assigned to select the first 8 channels on frequency table of the appropriate band for which the module is configured by pulling the P1-P3 pins low. Channel select pins of TR2M have internal pull-up to 4V supply rail, hence channel selection operate on inverted logic. Channel 0 1 2 3 4 5 6 7 P3:P2:P1 111 110 101 100 011 010 001 000 433MHz band 433.050 433.075 433.100 433.125 433.150 433.175 433.200 433.225 458MHz band 458.525 458.550 458.575 458.600 458.625 458.650 458.675 458.700 Digital Received Data Output (RXD) pin is an open collector output, which should be pulled-up to required voltage swing level (e.g. +4.4V or Vcc). TR2M has an automatic noise squelching function which 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 received. 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. 1kΩ) according to the current requirement to produce satisfactory brightness on the LED used. TR2M can be configured using any PC/Laptop/PDA having a serial port and modem/terminal program. TXD (pin 3) of DB9M connector can be directly wired to PGM (pin C10) of the TR2M and SGN (pin 5) of DB9M connector should be either connected to common ground or pin C9 of the TR2M. The whole frequency/channel table is user reconfigurable to 128 channels within 5MHz band of supplied frequency subject to regulatory band limits. Serial Channel Selection via PGM pin gives access to the whole of regulatory band allocation for 433.05MHz-434.790MHz (69 channels) or 458.525MHz458.925MHz (23 channels). Radiometrix Ltd TR2M Data Sheet PC serial port SQF (MOD NC) (C5) Host Microcontroller Data Out 1 page 4 Received Signal Strength 2.5 2.3 2.1 1.9 RSSI output (V) 1.7 1.5 1.3 1.1 0.9 0.7 0.5 -130 -120 -110 -100 -90 -80 -70 -60 -50 -40 RF Level (dBm) Figure 5: RSSI voltage variation with respect to RF level at TR2M If the microcontroller has a built-in Analogue to Digital Converter (ADC), the Received Signal Strength Indicator (RSSI) output voltage level can be read by the microcontroller to estimate its distance from transmitting TR2M unit or identify areas 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. Regulatory Restrictions There is a generic 10% duty cycle restriction on the 433MHz ISM band through out European countries with few exceptions. Annex 1 Band E, Band E2 of European Radio Communications Committee (ERC) Recommendation 70-03 dated February 2004 specifies the following: 433.050MHz (Ch0) 434.050MHz (Ch40) 10mW ERP, 10% duty cycle for Channelised Narrow Band and Wide Band usage 10mW ERP, 100% duty cycle for