HOW TO USE THIS PUBLICATION
This publication provides information on 2120 Multiplex systems equipped with 2001 voice communications
equipment. Typical equipment configurations are illustrated, as are specific interconnections between 2120 and
2001 equipment.
This manual is divided into the following sections:
. MAIN EQUIPMENT
. REMOTE EQUIPMENT
. CLASS A AUDIO
Each of these sections is divided into subheadings covering specific topics.
IMPORTANT!
This manual is intended for those who already have a solid background in 2120 Multiplex systems
and 2001 Voice Communications equipment. Refer to 2120 and 2001 voice communications
training materials for basic information.
FOR MORE DETAILED INFORMATION.. .
refer to the documents listed below.
2001 Voice Communications Wiring Diagrams
2001 Systems Troubleshooting Guide
2001 Voice Communications Module Descriptions
BMUX with Voice Communications interconnection, W.D. No. 801-529
2120 Multiplex System Installation manual
System interconnection drawings for the specific installation
Equipment cabinet drawings for the specific installation
M-21 20 and M-2120~ET initiating wiring diagrams
INTRODUCTION
2120 Multiplex systems that use 2001 voice communications equipment are configured differently from their 2001
counterparts. Since 2120 systems fall in the “large building” or “building complex” range of applications, a 2120
system equipped with voice communications equipment requires a special approach to system set up - we don’t
want to lose the multiplex advantage just because we want voice communications.
One major difference is shown in Figure 1. Since we must provide audio signals to each building floor, 2120
systems use what we call an
audio riser.
An audio riser is typically a single wire pair that carries an amplified
audio signal to transponder cabinets where the audio signal is applied to FABT or ET speaker circuits (via audio
relay boards). As you can see in the block diagram, most FABT or ET cabinets that contain audio relay boards
also contain an
audio interface transformer
and a
remote amplifier.
The BMUX equipment cabinet contains the voice communication equipment required to originate system audio
signals. The SCC cabinet, usually close-nippled to the BMUX cabinet, contains what we call the
power preamp.
This preamp boosts the original audio signal so that the signal can make it to its destinations without loss of
quality. The equipment in the BMUX cabinet is connected to equipment in the SCC cabinet via a harness
assembly; the BMUX’s local BT is used to monitor and control both BMUX and SCC audio equipment conditions.
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