Expansion Nest Numbering Sequence; Connecting External Alarms - Paradyne HOTWIRE 7900 User Manual

MTU-M Installation Procedures

Expansion Nest Numbering Sequence

Connecting External Alarms

2-4
A fully populated equipment rack with four 19-inch Hotwire Model 7900 nests and
one MTU-M holds 63 nest card termination units. There are 15 nest card
termination units in the first nest (primary nest with MTU-M installed) and 16 in
each adjacent nest. Nest card termination units are numbered from left to right
(from the front of the nest) as follows:
In Nest . . .
1 (primary)
2
3
4
NOTE:
MTU-M menus allow you to select xTU IDs from 2–80. This number reflects a
potential 23-inch nest option. Each 23-inch nest would hold up to 20 nest
card termination units. A fully populated equipment rack (with four 23-inch
nests) could contain up to 80 nest cards (a single MTU-M and 79 termination
units).
The MTU-M provides dry alarm contacts that allow you to connect external
alarms to the nest rear panel at J21. The Alarm contacts are energized by the
MTU-M upon detection of an alarm condition. Each alarm relay, when closed,
connects your alarm power to your common to complete your Major and
Abnormal alarm circuits. The Minor alarm relay is not currently supported.
Procedure
To connect your external alarms to the rear panel alarm terminal (J21):
1. Connect alarm ground to the terminal labeled COM.
2. Connect your abnormal alarm circuit to the terminal labeled ABNM.
3. Connect your major alarm circuit to the terminal labeled MAJ.
March 1998
Nest Cards are Numbered . . .
2–16
21–36
41–56
61–76
7900-A2-GB20-00