Radiometrix Ltd.

UHF FM Radio Packet Modem

page 13

Built into the configurator is a diagnostic test suitable for range testing and link confidence testing. The

Radar test effectively sends a small request packet to a remote unit then waits for a reply. The remote

unit must not be in the configurator otherwise it will not respond.

Upon receipt of a positive response from the remote unit, a success is recorded before the process is

repeated. This test will continue indefinitely until it is ended by a key press.

4.6 Radio Packet Modem Error Handling

The RPM3’s radio decoder module is deliberately non bit error tolerant, i.e. no attempt is made to repair

corrupt data bits. All of the redundancy in the code is directed towards error checking. For an FM radio

link using short packet lengths, packets are either 100% or so grossly corrupt as to be unrecoverable. By

the same reasoning, the Host is not informed or sent corrupt data since corrupt information is of little

value. The RPM3 implements packet acknowledges, timeouts and re-transmission to accomplish reliable

error handling.

Ordering information

Part number

European: 869.85MHz

Supply SMA

Connector

SMA

Antenna

RPM3-869-17

5V

RPM3-869-17-3V

3V

RPM3-869-17-SMA

5V

Yes

RPM3-869-17-3V-SMA

3V

Yes

RPM3-869-17-ANT

5V

Yes

Yes

RPM3-869-17-3V-ANT

3V

Yes

Yes

Part number

North American: 914.5MHz

Supply RPSMA

Connector

RPSMA

Antenna

RPM3-914-17

5V

RPM3-914-17-3V

3V

RPM3-914-17-RPS

5V

Yes

RPM3-914-17-3V-RPS

3V

Yes

RPM3-914-17-ANT

5V

Yes

Yes

RPM3-914-17-3V-ANT

3V

Yes

Yes

Notes:

1. Standard RPM3 module will be supplied with neither the connector nor antenna and RF pin (2).

2. If an SMA (or Reverse Polarity SMA) connector or 1/4 wavelength wire antenna is soldered on the

protruding PCB section for SMA connector, then the RF pin (2) should be cropped with side

cutters for better RF performance.

3. If the RF output is going to be taken from the RF pin (2) to on-board antenna or connector on the

host PCB (motherboard) via 50

Ω microstrip, the protruding section of the RPM3 PCB can be cut

along the width of the RPM3 to remove the redundant connector section.

4. RPM3 is supplied with 7mm long pins which need to be trimmed to mount the module as close as

possible to the host PCB (motherboard). Ideally, the black coloured plastic spacer on the RPM3

pinheader should be touching (resting on) the host PCB.

5. North American version can also be supplied with SMA connector and antenna. However, only

the RSPMA antenna version is approved under FCC Part 15.249.