User's Manual

Company Confidential 39 Raveon Technologies Corp.
with a pre-set value, and if it is above this value, Carrier Detect is asserted. The
pre-set value may be change with the ATRA command.
When the modem is used in the Streaming Mode (non-packetized operation, you
may wish to configure the modem to require RF carrier detect to be active for the
modem to receive data. Use the ATRF command to enable/disable this feature.
To set the RF carrier detect level, perform the following steps:
1. Generate a test signal, 1kHz tone, 1.5kHz deviation, on the receive
frequency. Connect the signal generator to the antenna input. Turn the RF
level off.
2. Watch the RSSI value by issuing the AT$5 command. The current reading
will be sent out the serial port.
3. Adjust the RF level to a point where you would like the RSSI to trigger the CD
signal. This is factory-set to -110dBm.
4. Send the ATRA nnn command. Set nnn to be equal to the RSSI setting you
would like the CD signal to trip at. The BUSY LED will also indicate an RF
carrier when the RF carrier is above the threshold set with the ATRA
command.
5. Generate an RF signal on-channel with a level of -110dBm. Verify the
Power/BUSY LED stays on. If it does not, repeat step 4, adjusting in
increments of 10.
8.7. MURS Operation
This product is used on frequencies governed by the FCC rules part 95, Subpart
J, (Multiple Use Radio Service operation). The pre-set MURS channels are:
1 151.820 MHz
2 151.880 MHz
3 151.940 MHz
4 154.570 MHz
5 154.600 MHz