EW
N
Issue 1, 30 April 2007
Radiometrix
Hartcran House, 231 Kenton Lane, Harrow, HA3 8RP, England
Tel: +44 (0) 20 8909 9595, Fax: +44 (0) 20 8909 2233
TXL2/RXL2
UHF Multi Channel Transparent Data Link TX/RX
The TXL2 and RXL2 modules are 9600baud
simplex multi channel OEM radio modems
in a Radiometrix SIL standard footprint,
operating on European 433MHz ISM band.
The TXL2/RXL2 pair act as a transparent
serial cable to attached host. Unlike raw
FM radio modules (e.g. TX2A/RX2A),
TXL2/RXL2 will take care of preamble,
synchronisation, bit balancing and error
checking along with automatic noise
squelching.
Figure 1: RXL2-433-9 radio modem receiver
The TXL2/RXL2 pair provides a one-way radio link. Provided no two devices attempt to transmit
simultaneously no further restrictions on data transmission need be made, as all transmit timing, valid
data identification and datastream buffering is conducted by the units. Synchronisation and framing
words in the packet prevent the receiver outputting garbage in the absence of wanted RF signal or
presence of interference. For multiple radio systems a TXL2/RXL2 can be set to 1 of 8 unique addresses.
As well as having unique addresses, the TXL2/RXL2 allow operation on one of 5 pre-set frequencies in
the 433MHz band. These frequencies are non-overlapping and simultaneous operation of TXL2/RXL2
pairs in the same area on different channels will be possible. Units are supplied on 433.925MHz (Ch0)
as default.
Features
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Conforms to EN 300 220-3 and EN 301 489-3
High quality, stable crystal reference
Low noise synthesiser / VCO
SAW front-end filter
Multi-stage ceramic IF filtering
Single conversion superhet
Serial modem baud rate at 9600bps (simplex)
Addressable point-to-point
5 serial select wideband channels
Applications
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PDAs, organisers & laptops
Handheld / portable terminals
EPOS equipment, barcode scanners
In-building environmental monitoring and control
Remote data acquisition system, data logging
Fleet management, vehicle data acquisition
Technical Summary
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Operating frequency: 433.925MHz (default)
Modulation: 16kbps bi-phase FSK
Supply: 5V at 28mA transmit, 22mA receive/idle
Transmit power: +10dBm (10mW)
Receiver sensitivity: -107dBm (for 1% BER)
32 byte data buffer
Adjacent channel rejection: 60db @ ±320kHz
Receiver Blocking: >75dB
TXL2/RXL2 Data Sheet
page 1
Radiometrix Ltd
Radiometrix Ltd
TXL2/RXL2 Data Sheet
Figure 2: TXL2 block diagram
page 2
42mm
7mm
18mm
TXL2
15.24mm (0.6")
1
2
3
4
5
6
7
0.3"
8
8 holes of 0.7mm dia.
pin spacing 2.54mm (0.1")
1 = RF gnd
2 = RF out
3 = RF gnd
4 = En
5 = Vcc
6 = GND
7 = TXD
8 = SETUP
Figure 3: TXL2 footprint
TXL2 Pin description
Pin
1
2
3
4
5
6
7
8
Notes:
1.
2.
3.
4.
5.
6.
7.
Name
RF GND
RF out
RF GND
EN
Vcc
GND
TXD
TEST/SETUP
Function
RF ground
50Ω RF output to the antenna
RF ground
Pull high to enable module (may be tied to Vcc)
5V regulated power supply (4.75 – 5.25V)
Supply ground
Inverted RS232 input (5V CMOS logic, No pullup)
Pull low to enter test/setup mode (5V CMOS logic, Pullup to 5V)
TEST has 47K pullup to Vcc. TXD has none. EN has a 47K pulldown
Vcc must be a 5v regulated supply (4.75 - 5.25v)
Pinout is similar to TX1H, with the addition of pin 8 (located 7.62mm on from pin 7)
TXD is inverted RS232 at 5v cmos levels. To connect to a true RS232 device, inverting a level shifter must be
used (MAX232 type are ideal, but simple NPN transistor switches with pullups often suffice). With typical
microcontrollers and uarts, direct connection is possible.
The TXL2 provides transmit side of a simplex link, but provided no two devices attempt to transmit at one
time, no further restrictions on data transmission need be made, as all transmit timing, valid data identification
and datastream buffering is conducted by the unit. There is no 'transmit enable' pin.
This unit is compatible with the RXL2 receiver and the TDL2A transceiver
A simple addressing structure is included in the datastream. Units may be programmed onto one of eight
addresses (all units are supplied set to default ADDR=0 and default channel=0, 433.925MHz)
Radiometrix Ltd
TXL2/RXL2 Data Sheet
page 3
Radiometrix Ltd
TXL2/RXL2 Data Sheet
Figure 4: RXL2 block diagram
page 4
47mm
7mm
17mm
RXL2
30.48mm (1.2")
1
2
3
4
5
6
7
7 holes of 0.7mm dia pin spacing 2.54mm (0.1")
1 = RF in
2 = RF gnd
3 = RSSI/BUSY
4 = 0V
5 = Vcc
6 = AF/PGM
7 = RXD
Figure 5: RXL2 footprint
RXL2 Pin description
Pin
1
2
3
4
5
6
7
Name
RF in
RF GND
RSSI/BUSY
0V
Vcc
AF/PGM
RXD
Function
50Ω RF input from the antenna
RF ground
S meter or BUSY output
Supply ground
5V regulated power supply (4.75 – 5.25V)
Baseband audio (or PGM in)
Receive Data (Inverted RS232 at 5V CMOS logic level); Input in
PGM mode
Notes:
1. To enter program mode, the AF/PGM pin must be tied to ground (Vpin below 0.3v: jumper or open collector
recommended). Normally this pin functions as a high impedence (20K) receiver baseband audio output
2. Vcc must be a 5v regulated supply (4.75 - 5.25v)
3. Pinout is as RX2A
4. RXD is inverted RS232 at 5v cmos levels. To connect to a true RS232 device, inverting level shifters must be
used (MAX232 type are ideal, but simple NPN transistor switches with pullups often suffice). With typical
microcontrollers and uarts, direct connection is possible. The same pin is uesd for normal operation Data out,
PGM mode data in, and PGM mode data out.
5. The RXL2 provides a receive side of a simplex link. Provided no two devices attempt to transmit at one time,
no further restrictions on data transmission need be made, as all transmit timing, valid data identification and
datastream buffering is conducted by the unit.
6. This unit is compatible with the TXL2 transmitter and the TDL2A transceiver.
7. A simple addressing structure is included in the datastream. Units may be programmed onto one of eight
addresses (all units are supplied set to default addr=0) and one of five RF channels (supplied default is
channel=0, 433.925MHz)
8. RSSI pin can be changed to a 'BUSY' (= valid data in FIFO) logic output by a solder blob link on the back of
the pcb, otherwise it functions as a signal strength output (0 - 1.4v)
Radiometrix Ltd
TXL2/RXL2 Data Sheet
page 5
Microcontroller MCU
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