DEFINITY Enterprise Communications Server Release 7
Maintenance for R7r
555-230-126
Issue 4
June 1999
Alarms, Errors, and Troubleshooting
5-89Packet Bus Fault Isolation and Repair
5
TN771D in Standalone Mode
In TN771D standalone mode, a terminal is connected to the Maintenance/Test
circuit pack with an Amphenol connector on the back of the cabinet. This setup
allows direct inspection of the packet bus and identifies shorted or open leads.
This mode does not use the usual MT Maintenance User Interface and is thus
available even if switch is not in service. When in standalone mode, the TN771D
does not reconfigure the packet bus.
Required Hardware
■ TN771D: Standard or High Reliability systems may not have a TN771D in
each EPN. (Use
list configuration
to determine if this is so.) When this is
the case, one must be taken to the site. See the following section,
‘‘Special
Precaution Concerning the TN771D’’.
■ Terminal or PC with terminal-emulation software: The EIA-232 (RS-232)
port should be configured at 1200 baud, no parity, 8 data bits, and one
stop bit. This is
not
the same configuration as for the G3-MT. If a terminal
configured as a G3-MT is used, change the SPEED field from 9600 to
1200 on the terminal’s options setup menu. (This menu is accessed on
most terminals by pressing the CTRL and F1 keys together. On the 513
BCT, press SHIFT/F5 followed by TERMINAL SET UP). Remember to
restore the original settings before returning the G3-MT to service.
■ 355A EIA-232 Adapter (Comcode 105 012 637).
■ 258B Six-Port Male Amphenol Adapter (Comcode 103 923 025). A 258A
Adapter and an extension cable can also be used.
■ D8W 8-wire modular cable of an appropriate length to connect the 258A
on the back of the cabinet to the 355A adapter. The relevant Comcode is
determined by the length of the cable, as follows:
— 103 786 786 (7 feet)(2.1 m)
— 103 786 802 (14 feet)(4.3 m)
— 103 786 828 (25 feet)(7.6 m)
— 103 866 109 (50 feet)(15.2 m)
Slot Selection for Standalone Mode
When selecting a carrier slot to use for standalone mode in a port network that
does not already contain a TN771D, keep the following points in mind:
■ A port circuit slot (indicated by a purple label) should be used. The
service slot (slot 0)
cannot
be used for standalone mode, although a
TN771D may normally be installed there.
■ -5 volt power supply must be available in the carrier. (Refer to
‘‘CARR-POW (Carrier Power Supply)’’
in Chapter 9, ‘‘Maintenance Object
Repair Procedures’’ for a description of carrier power supply units.)
