Programming instructions

APPENDIX F - T1 MAINTENANCE
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3) Click Clear T1 Error to clear the errors as specified in step 3.
• A message will appear to let you know whether or not the request was successful.
4) Click OK to close the Send success screen.
Red Alarm
A Red Alarm occurs in the following situations:
• at startup until the system establishes synchronization with a
good link
• whenever a receive signal is not present
• when the system receives a blue alarm from the network
• whenever a yellow alarm, sent from the network, is active for
more than 2.5 seconds.
Yellow Alarm
• The network sends a yellow alarm to the T1 framer for
detection.
• This alarm indicates that the network has detected a transmit
signal from the T1 board but cannot synchronize to the
transmit frame.
• If a yellow alarm is in effect for more than 2.5 seconds, the
system activates a red alarm.
• If the network removes a yellow alarm within the 2.5 seconds,
the system will return to normal.
• When a yellow alarm occurs, it is a good practice to check the
network wiring.
• The yellow indicator on the T1 board also indicates this
condition.
Blue Alarm
• The network sends a blue alarm (also known as an Alarm
Indication Signal or AIS) for detection by the T1 framer.
• This alarm signal consists of all ones on all channels and is
an indication that the network is unable to detect any signal
being transmitted from the T1 board.
• This condition will immediately cause a red alarm. When you
see a blue (AIS) alarm, check the transmit signal.
T1 ERROR TYPES (continued)