T1 Fault Isolation; Communications - Toshiba Strata DK14 Installation And Maintenance Manual

DK424 T1

T1 Fault Isolation

To receive the "T1 ERROR DISPLAY" from a terminal (local or remote)
1. Establish communication with the terminal or PC using a communication software (e.g.,
Procomm®).
2. Enter the security code, and press Enter (or Return).
3. At the >MODE prompt, type DUMP (must be all caps), press Enter (or Return). The >D
prompt displays on your screen.
4. At the >D prompt, type T1ERR and press Enter (or Return). The display (see
shows all RDTU PCBs (DTUNO=1~DTUNO=8) even if the associated RDTU (1~8) is not
installed. The ERROR counter can only be reset by turning the DK424 OFF and ON.
Use
To exit the dump mode
At the >D prompt, type QUIT, press Enter (or Return); the >MODE prompt displays.
T1 Fault Isolation
T1 fault troubleshooting can be complex and may require expensive test equipment to perform the
necessary fault isolation. Because of the high cost, many dealers have not purchased T1 test
equipment. As a result, on a cutover when an RDTU does not synchronize or CO lines simply do
not function, the site technician can only check wiring and cabling. Without proper test equipment,
there is very little that can be tested.
This section provides some procedures that can be done without T1 test equipment to help find the
cause of a failure, or at least determine if system hardware is functioning properly.
The DK424 also provides T1 "in-service" monitoring which allows maintenance personnel to
detect line errors without introducing any disturbances on the line. This method of testing permits
maintenance personnel to monitor T1 performance without the expense of test equipment or
without taking the T1 circuit out of service. The T1 error check is particularly useful for
monitoring the T1 circuit for intermittent problems that may become more serious as time
progresses (see
If experiencing problems with an RDTU span circuit, refer to
fault. The flowcharts in this section use the same logic symbols as those used in DK. Document
error information in
6-20
Table 6-2 for recording customer's problems.
"RDTU Performance Monitor Printout"
Table 6-2, "RDTU T1 Error Record"
on Page 6-19).
Flowcharts 6-1~6-3
on Page 6-21.
Strata DK I&M
Figure 6-10)
to isolate the
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