Merlin 3070 Service And Maintenance Manual page 166

This Services Module (Figure 1) is optional and not essential for basic system opera-
tion. When installed in position 6 (color coded yellow) of the communications system.
Model 1030 control unit , it provides connections for auxiliary equipment as follows:
Up to four power failure transfer telephones
Extra alerts (3 jacks)
Single or multizone paging system
Music source (input jack)
In addition, the module provides:
Background music volume control
Music-on-hold volume control
Page signal ON/OFF switch for paging alert
Level HI/LO switch for control of music input signal.
Figure 1. Service Module
LATCH