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 c onnected to the Maintenanc e/Test
circuit pack with an Amphenol connector on th e back of the cab inet. This setup
allows direct inspec tion of the packet b us and identifies shorted or open leads.
This mode does not use the usual MT Maintenance User Inter face and is thus
available even if switch is not in servic e. When in standalone mode, the TN771D
does not reconfigure the p acket 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 c onfigured 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 (Comcod e 105 012 637).
■258B Six-Port Male Amphenol Adapter (Comc ode 103 923 025). A 258A
Adapter and an extension c able can also b e used.
■D8W 8-wire modular cable of an app ropriate length to c onnect the 258A
on the back of the cab inet to the 355A adapter. The relevant Comc ode is
determined by the leng th 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 stan dalone mode in a port network that
does not already contain a TN771D, keep the following points in mind :
■A port circuit slot (i ndicated by a purple label) should be used. The
service slot (slot 0)

cannot

be used for standalone mo de, 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 descrip tion of carrier power supp ly units.)