PEB 2091
PEF 2091
Operational Description
Note 50: In LT and COT modes a FEBE will not be actively indicated by the IEC-Q. To
monitor NEBE violations the NEBE counter should be read out, see "Block
Error Counters", page 178.
Note also that although the FEBE bit is part of the MON-2 indication, a change
of the Single bit FEBE alone (i.e. if all other Single Bits didn’t change) will not
initiate a MON-2 indication in any filtering method setting of Single Bits
indications, see "Single Bits Reception from U", page 120 for more
information.
4.5.1
Block Error Counters
The IEC-Q provides internal counters for far-end and near-end block errors. This allows
a comfortable surveillance of the transmission quality at the U-interface. One block error
thus indicates that one U-superframe has not been transmitted correctly. No conclusion
about the number of bit errors is therefore possible.
4.5.1.1 NEBE Counter
Each detected NEBE will cause the NEBE counter to be incremented. The maximum
count is FFH. No further incrementation will be done after maximum count is reached.
Read Out and Reset
Issuing the MON-8 command RBEN will cause the IEC-Q to respond with the MON-8
indication ABEC consisting of the NEBE counter value in the second byte of the two byte
Monitor Channel indication. For more information about MON-8 codes, refer to "MON-8
Codes", page 228.
MON-8
0
RBEN
0
Read Block Errors Near-end
1
1
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
0
1
1
MON-8
0
ABEC
0
Answer Block Error Counter
C7 C6 C5 C4 C3 C2 C1 C0
C0 … C7: 8-bit counter value
Each read operation resets the NEBE counter to 00H. The counter is also reset in all
except the following states:
Semiconductor Group
178
Data Sheet 01.99