EW
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Issue 2, 06 October 2006
Radiometrix
Hartcran House, 231 Kenton Lane, Harrow, HA3 8RP, England
Tel: +44 (0) 20 8909 9595, Fax: +44 (0) 20 8909 2233
TDH2
UHF Multi Channel Hi Power Radio Modem
The TDH2 is a 9600baud half-duplex multi
channel OEM radio modem with a power output
of 25mW. It is a 100% pin-compatible drop-in
replacement for the Radiometrix TDL2A and
can be used to replace the TDL2A in
applications where greater radiated power is
desired. TDH2 acts as a transparent serial
cable to attached host. TDH2 is an intermediate
level OEM radio modem which is in between a
raw FM radio module like BiM2 and a
sophisticated OEM radio modem like SPM2. It
takes care of preamble, synchronisation, bit
balancing and error checking along with
automatic noise squelching.
Figure 1: TDH2-433-9 radio modem
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 unit. 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 (polled networks)
a TDH2 can be set to 1 of 8 unique addresses. As well as having unique addresses, the TDH2 allows
operation on one of 5 pre-set frequencies in the 433MHz band. These frequencies are non-overlapping
and simultaneous operation of TDH2s 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 Australian/New Zealand AS/NZS 4268:2003
High quality, stable crystal reference
Low noise synthesiser / VCO
SAW front-end filter and multi-stage ceramic IF filtering
Single conversion superhet
Serial modem baud rate at 9600bps (half-duplex)
Addressable point-to-point
5 serial select wideband channels
Available as TDH2T transmitter and TDH2R receiver for one way communication
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 50mA transmit, 22mA receive/idle
Transmit power: +14dBm (25mW)
Receiver sensitivity: -105dBm (for 1% BER)
32 byte data buffer
Adjacent channel rejection: 60dB @ ±320kHz
TDH2 Data Sheet
page 1
Radiometrix Ltd
RADIOMETRIX [ RADIOMETRIX LTD ]
