Chapter 2 Telephony hardware 39
Installation and Maintenance Guide

Global Analog Trunk Module (GATM)

The GATM was introduced with the BCM 3.0 sof tware load. This module provides an interface to
the telephone company analog line s for the Business Communication Manager. The module
supports both pulse and tone dialing, Call er ID, and Supervision Disconne ct in various markets.
In North America, this module supe rsedes the Caller ID Trunk module (CTM).
UK profile configuration note: The GATM does not support Earth Calling even though the option
appears in the Unified Manager Lines record. Only a FEM connected to a Norstar analog trunk
module supports this feature.
The figure below shows the front of the GATM module. Note that both the GATM4 and the
GATM8 have only one amphenol connector. The firmware differentiates how many lines the
connector supports.
Figu re 16 GATM4/GATM8 module faceplate
Transmit Alarm On indicates the DTM cannot transmit. The DTM sends an Alarm indication signal
(AIS) to the terminating switch. This half-duplex link does not work.
Transmit Error On indicates the DTM is sending a remote alarm indication (RAI) carrier failure
alarm (CFA) to the terminating switch. If the Transmit Alarm is not on, this error
indicates a far-end or cable problem.
All LEDS flashing All LEDs flashing continuously indicates that the DTM is initializing.
TIP: You can install a maximum of three DTMs in the BCM1000 system, depending on
the available bus blocks.
These modules must be installed in the BCM1000. If you already have three modules
installed in the BCM1000, move one of those modul es to the expansion unit to provide
space fo r the DTM
Tab le 4 DTM LED functions (Continued)
LED label Function
Power LED
Status LED
Amphenol
connector