User's Manual

Company Confidential 45 Raveon Technologies Corp.
11. Troubleshooting
Symptom: Unit will not receive
Solution #1. Verify that the modem is on the correct RF channel. If it is, the RX LED should
blink every time another modem tries to transmit to it. If the RX LED does not blink when it
should be receiving, it is on the wrong RF frequency.
Soultion #2. If the addresses match, and RX LED blinks but still no reception of data, verify
that the RTS signal is asserted. The FireLine will not output data if the RTS signal on the DB-9
I/O connector is not asserted. If the user’s hardware cannot assert the RTS hardware line,
disable hardware flow control in the FireLine modem, using the ATCH 0 command.
Solution #3. If the RX LED blinks, verify that the Unit Address of the sending modem matches
the unit address of the receiving modem. If this is OK, verify that the over-the-air baud rate of all
modems is the same (ATR2 command).
Symptom: Unit will not transmit
Solution #1. Verify that CTS is wired. Some devices that could be connected to the FireLine
will require the CTS signal to be asserted. The FireLine does assert this signal, but if the wire is
not connected, you device may not be outputting data to the FireLine. If the TX LED blinks, the
FireLine is transmitting data. Every time data enters the modem, the TX LED should blink
Solution #2. Verify that serial port timeout is OK. The ATG0 command sets the number of
microseconds that the FireLine will look for in the serial input data stream. If a pause greater than
this value happens, the modem will transmit. If the ATG0 paramter is set very large, say
2000000, this means 2 seconds, and the modem may simply be waiting a long time
Solution #3. Verify that the radio channel is clear or BCL is off. The ATBC 1 command
enables Busy Channel Lockout. If BCL is on, the modem will not transmit on a busy channel.
The ATBC 0 command turns it off, and thus the modem will transmit when it needs to, regardless
if the channel is busy. The RX led on the front of the modem is illuminated whenever the radio
channel is busy (RF present).
Symptom: Long delay before transmitting
Solution #1. Verify that serial port timeout is OK. The ATR3 command sets the number of
milliseconds that the FireLine will look for in the serial input data stream. If a pause greater than
this value happens, the modem will transmit. If the ATG0 parameter is set very large, say 2000,
this means 2 seconds, and the modem may simply be waiting a long time. Typical settings for
this parameter are 20 (20mS).
Symptom: Modified parameters are lost at power-up
Solution #1. Issue an ATSV command. After any parameter is modified, the modem will
operate with the new setting, but unless the ATSV command is issued, it will revert to the old
setting upon turning power off and back on again. The ATSV command saves all parameters into
EEPROM memory, and these saved parameters are restored upon power up.
Symptom: Cannot enter Command Mode
Solution #1. Verify the serial port baud rate. This is difficult if it is set wrong, because you
cannot enter the command mode to check it. Try all possible baud rates, and see if one of them
works with the modem. Alternately, remove the rear cover of the modem, and press the CONFIG
button. This will force the modem into the Command Mode, as well as set the serial port to 9600
baud, 8 data bits, one stop, and no parity. If the baud-rate was OK, verify the AT, BT and CT
times, that they are long enough for you to enter the +++ string.