AT&T MERLIN LEGEND Communications System Release 2.0 Maintenance And Troubleshooting Manual page 209

Glossary
frequency generator
A circuit pack added to the power unit module that generates a high-voltage,
20-30 Hz signal to ring a telephone. Also called a ring generator.
FX (foreign exchange)
A central office (CO) other than the one providing local access to the public
network.
glare
The loud dual-tone multi-frequency (DTMF) signal an incoming caller hears
when another caller tries to call out on a trunk at the same time the call is
coming in on that trunk.
ground-start (GS) trunk
A trunk on which, after verifying that the trunk is idle (no ground on tip), the
communications system transmits a request for service (puts ground on ring)
to a distant central office (CO).
headset
An ultralight earpiece and microphone for hands-free telephone operation.
HFAI
Hands Free Answer on Intercom
Hybrid/PBX
A mode of operation in which the communications system uses trunk pools
and Automatic Route Selection (ARS) in addition to personal lines — that is,
direct facility terminations (DFTs) on line buttons. The Hybrid/PBX mode also
provides a single interface to users for both internal and external calling.
ICOM
Intercom
immediate-start tie trunk
A tie trunk on which no start signal is necessary and dialing can begin
immediately after the tie trunk is seized.
Glossary GL-7