Avaya MCC1 Maintenance Procedures page 230

Packet and serial bus maintenance
Isolating and repairing packet-bus faults
Figure 66: Stand-alone mode confirmed
Command:
NOTE:
If the previous display does not appear, check the wiring between the terminal and the
TN771D, and the terminal parameters settings. If these are correct, the TN771D may be
defective. In such a case, use the following procedures to exit stand-alone mode, and then
test the Maintenance/Test circuit pack. Refer to
and
alone mode, the message TN771 circuit pack failed is displayed, and no further
input is accepted on the terminal. The circuit pack must be replaced.
To exit stand-alone mode:
1 Remove the 258A adapter from the Amphenol connector.
2 If the TN771D was installed for this procedure, remove it. Otherwise, reseat the TN771D.
3 If change system-parameters maintenance was used to disable alarm origination, re-enable it
now.
Packet bus fault isolation and correction in
stand-alone mode
When the TN771D is in stand-alone mode, three commands are available:
Figure 67, Stand-alone mode display,
230
TN771 STAND-ALONE MODE
(Type "?" at the prompt for help)
M/T-PKT (Maintenance/Test Packet Bus
ds Displays the current state of the packet bus leads.
dsa Toggles auto-report mode on and off. In auto-report mode, the state of
the packet bus leads are displayed and the terminal beeps whenever a
change occurs.
? Displays the available commands.
on page 231 shows the state of the packet bus leads.
M/T-BD (Maintenance/Test Circuit Pack)
Port). If the TN771D fails while in stand-
Maintenance Procedures
December 2003