6
Issue 14, April 2003
64200376L1-5A
Figure 6. Alternate Power Connection
Office Alarms.
Backplane alarm connections (P5) are
labeled as shown in Table 2 on page 6 and illustrated in
Figure 7 on page 6. Alarm relay contacts are open
during normal operation. The alarm relay contacts close
in the event of a local alarm condition or the receipt of
an alarm from the T1 carrier. In a carrier alarm
condition such as a Red, Yellow, or Blue (unframed all
1s), various alarm contacts in the PSU close. Carrier
alarm conditions cause the Total Access 850 to initiate
trunk processing. The following chain of events then
occur:
1. MJ will be directly shorted to MJR.
2. MJV will be directly shorted to MJVR.
Contacts MJ and MJR can be overridden manually
during an alarm condition by pressing the ACO
pushbutton on the PSU faceplate. If the 3-Amp power
fuse on the PSU trips, the -48ALM relay will close,
providing a -48 VDC signal on that pin. This alarm
cannot be overridden by the ACO pushbutton. Refer to
Table 3 on page 6 for alarm notifications.
Table 2. Wire Wrap Identification
Figure 7. Office Alarm Connections
Table 3. Alarm Notification
NOTE
The following section is for information only, and
the features described are not necessary for typical
applications.
P3 Wire-Wrap Connections
T1 Connections
1
R1
DS1 Ring input from network
2
T1
DS1 Tip input from network
3
R
DS1 Ring output from network
4
T
DS1 Tip output from network
5
Gnd
Ground
P5 Wire-Wrap Connections
Alarm Connections
1
-48 ALM DC Alarm output
2
MJVR
Major Alarm Visual Common
3
MJV
Major Alarm Visual
4
MJR
Major Alarm Audible Common
5
MJ
Major Alarm Audible
Alarm Condition
Relays Activated
MJR
MJVR
-48 ALM
Red Alarm
X
X
Yellow Alarm
X
X
AIS Alarm
X
X
PSU Power Fuse Fails
X
X
X
Alarms ACO Deactivates
X
X
Note: ACO will not deactivate MJR after a power fuse
failure.
