AT&T MERLIN LEGEND Release 3.0 Installation Manual page 107

Installing Adjuncts
Dual-Tone Multifrequency (DTMF) Signaling
You can connect external paging systems that use dual-tone multifrequency
(DTMF) signaling, such as PagePac
systems, to an LS or GS line/trunk jack programmed for paging operation,
including bidirectional paging operation (talk-back). PagePac Plus does not
require an adapter.
Zone paging systems, such as the PagePac series, require one LS or GS
jack. You can use any zone once the paging jack is activated.
You must use a Universal Paging Access Module (UPAM), or PagePal (for
PagePac series systems other than PagePac Plus) to connect a paging
system that requires contact closure, an impedance-matching transformer, or
both.
Use a Loop Start Trunk Adapter when a customer-supplied paging system
does not require contact closure.
3-30 Installing Telephones and Adjuncts
®
Plus with Zone Expansion Unit paging