Specifications

Copyright © AMETEK
12
Both of the two-wire voice modules described in
this chapter (V2W and V2T) are available using
either standard ANSI voice encoding (µ-law) or
standard CCITT voice encoding (a-law). The
description, application, installation, operation,
status indicators, module layouts (component
locations), and schematics are identical for the
two variations of each module.
Although the FCS refers to both variations of the
V2T module as “V2T,” the module itself is labeled
“V2T-a” for the a-law version and “V2T-µ” for
the µ-law version. Likewise, the FCS refers to
both variations of the V2W module as “V2W,”
while the module itself is labeled “V2W-a” for the
a-law version and “V2W-µ” for the µ-law
version.
This chapter, like the FCS, refers to both varia-
tions of the V2T module as “V2T” and to both
versions of the V2W module as “V2W.”
12.1 Description
The V2T/V2W modules provide two-wire voice
and data communication between two locations.
The V2W is an originating module; the V2T is a
terminating module. Both modules support two
channels, A and B, which you can configure and
use independently.
The V2T/V2W interface module includes RJ-9
jacks and a compression-type terminal block for
connecting two-wire telephone wires directly.
Both types of interface provide connections for
two channels, A and B, which correspond to the
two channels, or time slots, on the T1/E1 line.
The V2T/V2W has a programmable gain control
that you can set, or configure, using the FOCUS
Configuration Software (FCS). The maximum
input offset is -7dB. The maximum output offset is
0dB. The preset insertion loss is 2dB.
Table 12-2 shows the module’s technical specifi-
cations.
12.2 Application
The dual channel design of the V2T/V2W
modules and the two types of interface connec-
tions gives you several configuration and usage
options.
You can use two V2W modules to provide a point-
to-point intercom capability or a V2W/V2T pair
for a remote telephone extension. Following are
the descriptions for both types of applications.
For either type of application, you can use the
FCS to configure the module’s channel A and B
independently. That is, you can set the filter gain
level input/output offsets differently for each
channel. For specific configuration instructions,
please refer to the FCS online help facility
(Configuring the FOCUS Channel Modules >
Two-Wire Voice Module (V2W/V2T)…).
The FXS module is a special version of the V2W
used when interfacing with an FXO module
requiring inverted signaling.
Figure 12–1. Intercom Connection.
12.2.1 V2W Intercom Capabilities
The FOCUS intercom application (ring down)
provides a point-to-point communications circuit
using two 2-wire voice originating (V2W)
modules and two standard telephones, as shown in
Figure 12-1. The signal is transmitted over a
single DS0 channel in the FOCUS system. The
two modules making up a circuit must be mapped
to the same channel, or time slot. Likewise, the
FOCUS Link
(
V2W Channel
Module
(
V2W Channel
Module
12. Two-Wire Voice (V2T/V2W, FXS, FXO)