Fault Isolation; Stored Faults - Comtech EF Data KST-2000B Installation And Operation Manual

Ku-Band Satellite Transceiver
Fault Indication and Isolation
4.2

Fault Isolation

System faults are reported on the Fault Log screen in the Windows™ based remote M&C
software. (Alternatively, they may be viewed in the terminal mode as shown in
Appendix B). Table 4-1 lists the KST-2000A/B faults and their indication in the LEDs
and relays. In some cases, items listed in Table 4-1 give no LED or relay indication when
they occur because they are not equipment faults but are useful for troubleshooting prob-
lems.
4.3

Stored Faults

Each of the major modules within the KST-2000A/B (Upconverter, Downconverter,
HPA, LNA/LNB, and Reference), together with the AGC function and the Common
Equipment, report their individual fault status to the main M&C. Each time there is a
change in the fault status, that status is stored in a non-volatile memory on the main
M&C. Note that each event corresponds to a change in status. Therefore, when a fault oc-
curs, that constitutes one status change, and when that fault clears, another event occurs.
The M&C can store up to 10 fault status conditions.
After 10 fault status changes are logged, no further logging can take place until the Clear
Stored Faults (<add/CLSF) command is issued. Refer to Appendix B, Table B-7 for the
fault commands to access the fault status of each function. When the fault status is que-
ried, such as <add/HS–, the response returned will indicate how many stored faults are
actually stored. To retrieve the individual fault status, issue the appropriate stored fault
command with the corresponding stored fault number, such as <add/HSF_2. That particu-
lar fault condition will be returned. Note that the stored fault numbers (locations) are 0
through 9 inclusive.
It is good maintenance practice to query the stored faults and record them in a logbook or
other permanent record and then issue the clear stored fault command, <add/CLSF_.
There is no time stamp associated with these stored faults. Noting them in a logbook is
the only way to establish an approximate time reference.
4–2
Revision 9
MN/KST2000AB.IOM