Specifications

Copyright © AMETEK
13
The four-wire voice module described in this
chapter (V4W) is available using either standard
ANSI voice encoding (µ-law) or standard CCITT
voice encoding (a-law). The description, applica-
tion, installation, operation, status indicators,
module layout (component location), and
schematics are identical for these two variations
of the module.
Although the FCS refers to both variations of the
V4W module as “V4W,” the module itself is
labeled “V4W-a” for the a-law version and
“V4W-µ” for the µ-law version.
This chapter, like the FCS, refers to both varia-
tions of the V4W module as “V4W.”
13.1 Description
The Four-Wire Voice (V4W) Module lets you
transmit both audio (voice and/or continuous
tone) and data, as well as E&M signaling infor-
mation (i.e., a voltage level). The standard
interface has two terminal blocks: one for the
audio/data; the other for the E&M signaling infor-
mation. Each terminal block provides both
channel A and channel B connections, which
correspond to the two channels, or time slots, on
the T1/E1 line.
The Multiple Voice Interface (MVI) takes the
output from up to three voice modules out of the
chassis via an AMP “Champ” 50-pin connector.
This is useful when the voice circuits need to be
terminated to jack fields, terminal blocks or RJ-
21X type terminations. Please see Table 13-2 for
circuit, chassis slot and channel assignments.
The E&M signaling information may be a voltage
level at a maximum of -48 vdc from one FOCUS
chassis to another. Incoming signals are received
on the channel’s “E” portion; outgoing signals use
the “M” portion.
The module can amplify an input signal to a
maximum of 23dB and attenuate an input to -7dB.
Table 13-1 shows the module’s specifications.
13.2 Application
The Four-Wire Voice (V4W) Module’s dual
channel design gives you considerable flexibility
in configuring and using it.
Using the FOCUS Configuration Software (FCS),
you can configure channel A and B independently.
You can set the transmit/receive gain offset, the
transmit/receive gain base, and the enable/disable
signaling option differently for each channel. For
specific configuration instructions, please refer to
the FCS online help facility (Contents > Channel
Module Configuration Overview > Configuring
the Four-Wire Voice (V4W) Module …).
As for flexibility in usage, you can transmit voice,
continuous tone (e.g., protective relaying, audio
tones), or data on either channel. Likewise, you
can disable one channel while transmitting on the
other
As noted earlier, the interface module provides
two terminal blocks, each with a channel A and B.
The audio block lets you connect audio tone
equipment, telephone wires for voice transmis-
sion, or a four-wire modem for data transmission.
The signaling block lets you connect a voltage
source for signaling.
For voice communications, you can connect either
one or two telephone lines (e.g., PBX trunk lines)
directly to the audio terminal block on the module
interface. E&M signaling must also be connected.
You can also attach, via a four-wire modem, any
device that uses a modem to transmit data. If you
do not have an RS232 module, this gives you a
low speed (9600 bps) modem connection for any
kind of data.
You can also use the signaling information to
close a contact, trigger an alarm system (e.g., a
SONALERT

attached to the FOCUS chassis at
the other end), etc. For applications using the tone
channel for protective relaying, the “Disable
Signaling” box should be checked in the
13. Four-Wire Voice (V4W) Module