Nokia MetroHopper User Manual page 54

Loop to interface
Severity: Major
Fault code: 21
Meaning: 1) Flexbus interface loop is active. The whole received Flexbus signal is looped back to the OU (or
another IU). The IU - OU communication will be cut during the loop.
2) Flexbus channel loop to interface is active. The whole received Flexbus signal is looped back to the OU (or
another IU).
3) Platform interface loop to interface active. The whole received platform signal is looped back to the OU (or
another IU) without regenerating time slot 0.
Instructions: Loops are normally used to locate faults.
Cancelling: A loopback will be removed automatically after a control timeout has expired. A loop can also be
removed with Manager back to the normal state.
Loss of CRC multiframe alignment
Severity: Critical
Fault code: 86
Meaning: Platform interface has lost CRC frame alignment.
Instructions: Check that the other end of the link has CRC in use. Use the same instructions as in the loss of
frame alignment to locate the fault.
Cancelling:
DN99611394 © Nokia Networks Oy
Issue 2-0 en
Unit/SB type:
1) Flexbus
2) Flexbus channel
3) Platform interface
Consequence: 1) AIS is connected to all received Flexbus channels.
2) AIS is connected to the receiving direction of the looped channel.
3) AIS is connected to the receiving direction of the looped interface.
Unit/SB type: Platform interface
Consequence: AIS is connected to the receiving direction of the platform interface.
Alarm descriptions
39 (42)