Possible causes and solution(s)

• Causes:

The heartbeat LED on the B426 is off.

No communication failure, trouble or communication module missing error messages at the keypad.

• Solution:

Check the TMPR pins next to the Ethernet port on the B426.

Remove the jumper from the pins, the B426s heartbeat LED will start flashing to show the firmware version on the board and then it will resume normal or trouble operation depending on the condition on the B426. When the Tamper jumper is covering both pins the heartbeat LED is turned off to save power.