Product manual

Maintenance, Test and maintenance software
Technical Product Manual - DCT1800-GAP
TD 92093 (1/LZBNB 103 108 R4D) / 2006-03-09/ Ver.C
© 2006
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• The board inserted in the system.
As a result the board power-on test is started on the board.
Watchdog reset
There are two different watchdog resets: an expected and an unexpected. An expected watchdog
reset happens during the watchdog test, which is the final test of the board power-on test.
An unexpected watchdog reset happens during normal operation, when a hard reset is given to the
CPU, the board controller or the controller within the base stations by their watchdog circuit.
A CPU watchdog reset results in a restart of the system.
A watchdog reset from a board controller results in a power-on test for that board.
Backplane reset (SW)
When the last board of the same kind is not responding any more, the system cannot work and
minimum configuration error occurs. DTUs and LTUs may be considered as functionally the same.
They both provide an interface for the system to a PBX. These boards are therefore called ‘of the
same kind’. When one of the elementary functions is not available any more, the CPU will force the
system to restart (power on test) to check what is wrong. Minimum configuration errors occur when:
• Last SPU function (SPU board, SPU-S board or SPU-S part on SLU board), is removed
• Last of all LTU/DTUs is removed (but not when the last DTU is removed, and still one LTU is
connected or vice versa)
• Last base station is removed. This can have two reasons:
– The last of all CLUs, CLU-S and SLUs is removed.
– The last base station of the last CLU, CLU-S or SLU is removed, while still having CLUs, CLU-
S or SLUs connected (connection of base stations is detected by the system).
T&M reset
When Test & Maintenance (T&M) detects an error, it sends a reset to the appropriate board controller
or peripheral, to start up a local test. When the fault persists, an error message will be written in the
service table and a general alarm is generated.
When the fault has disappeared, there will be no error signalling to the outside world, but the error
message remains in the fault table and the absolute and relative reset counters are incremented.
When the reset counter exceeds its threshold level, still an error message is written in the service
table and a subsequent alarm is generated.
2.4.2 Reset table
In order to keep a reset-history, the CPU has a reset table where all resets are counted for each board.
Also resets to the various circuits on the CPU board are counted. The values of all counters in the
reset table can be viewed by the menu System-Statistics Overview. Two counter types exist for counting
these resets: absolute counters and relative counters.
Absolute counters
An absolute counter counts all resets since the associated board is in the system. This counter is
cleared only at re-initialization or when the board is pulled out with a Board-Replace/Remove action
in CSM (in Distributor mode). Absolute counters have no threshold level.