User's Manual

Atlas PT Technical Manual

9. Troubleshooting

9.1 Symptom: Unit will not receive

Solution #1: Verify that the unit is on the correct RF channel. If it is, the Status LED

should blink green every time another modem tries to transmit to it. If the Status LED

does not blink when it should be receiving, it is on the wrong RF frequency.

Solution #2: If the Status LED blinks green, 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).

Solution #3: Verify the KEYPHRASE is correct. If encryption is used, the KEYPHRASE

is set to a unique word, and must be the same in all radios in the system. If it is not

used in the radio system, then the KEYPHRASE in all units must be disabled or left at

the factory default. To disable encryption, use the KEYPHRASE 0 command. The

factory default KEYPHRASE is RAVEON, in all capital letters.

Solution #4: Verify the Receiver circuits are powered. The receiver circuitry by default

is disabled (ATSM 4). If you wish to receive data with the ATLAS PT, you must enable

the receiver circuits, increasing the current draw a little bit. ATSM 0 enables the

receiver circuits.

9.2 Symptom: Unit will not transmit

Solution #1: Verify that the GPS is locked. If the Status LED is blinking twice per

second, the internal GPS is not receiving a signal from the GPS satellites, and thus, the

unit will not transmits. Locate the ATLAS PT in a place where it can receive a GPS

signal.

Solution #2: 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 Status led on the front of the modem is

illuminated green whenever the radio channel is busy (RF present).

9.3 Symptom: Receive light blinks, but no data is received

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 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.

Solution #2: Verify the KEYPHRASE is correct. If encryption is used, the

KEYPHRASE is set to a unique word, and must be the same in all radios in the system.

If it is not used in the radio system, then the KEYPHRASE in all units must be disabled

or left at the factory default. To disable encryption, use the KEYPHRASE 0 command.

The factory default KEYPHRASE is RAVEON, in all capitol letters.