AT&T MERLIN LEGEND Installation & Maintenance Manual page 541

Adapters, Accessories, and Applications
If PFT telephones are to be connected to GS lines/trunks, a
GS button (see Figure 66) must be added to each PFT
telephone. If the button is used with modular 2500
telephones, the button should be wired from the wall jack.
If rotary lines/trunks are used, rotary telephones must be used
as PFT telephones.
System Alarms
An alarm detected by the system can cause the CU to activate
contact closures at a GS or LS port (programming of an LS port
is preferred). When the contacts close, a signal is passed on to a
Universal Paging Access Module (UPAM) and then to an
external alert. Alerting devices can be a strobe, horn, bell, or
chime.
A UPAM is needed because 48-VDC alerting devices require
four contact closures and the GS or LS ports have only two. The
UPAM provides
Trouble Alarms
A GS or LS port
connected to the port via a UPAM (see Figure 69). When system
trouble (caused by hardware or software malfunction) is
detected by the operator console, a signal is sent to that port.
The port's switching contacts close and send the signal onto the
UPAM, which activates an external alert.
Power Failure Alarm
A GS or LS PFT port can be programmed to activate an alerting
device during a power failure. The device is connected to the
port via a UPAM (see Figure 70). When a power failure occurs,
the switching contacts on the PFT port close and send a signal
to the UPAM, which activates an external alert.
6-6 Accessories
the additional two.
can be programmed to activate an alarm