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
Multi-
Narrow 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)
P
in 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 1V
pk-pk
±10%
to keep distortion <1.5% and
peak deviation >2.5kHz
DC level between 0.5V and 2.5V. 60dB dynamic range
Noise operated carrier detect. Open collector. ON/low = no signal
200mV
pk-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 458.525MHz-
458.925MHz (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 <25kHz Channelised Narrow Band usage
433.05MHz
434.040MHz
434.79MHz
433.775MHz (Ch69)
433.050-434.790 MHz, Non Specific Short Range Device, band is primarily intended for Telemetry,
Telecommand, Alarms, Data in general and other similar applications. Audio and Voice signals should
be avoided in the band.
Radiometrix Ltd
TR2M Data Sheet
page 5
