Clear-Com CCI-22 - Manual (Page 11)

Vitec Group Communications
CCI-22 Dual Channel Party-Line Interface Instruction Manual 2 - 1
INSTALLATION
INTRODUCTION
This chapter describes the installation of the CCI-22 dual party-line
interface, including setting internal jumpers, wiring to external devices,
and setting front-panel controls and indicators.
INSTALLATION IN INTERFACE FRAME
To install the CCI-22 interface module in the IMF-3 or IMF-102
interface frame:
1. Select a slot in which to install the interface.
2. Remove the blank plate covering the slot.
3. Set any Party-Line Termination Jumpers as necessary.
4. Slide the CCI-22 in the slot and ensure that the card is fully seated.
5. Tighten the CCI-22’s front-panel mounting screws.
TERMINATION OF PARTY-LINES
A “Clear-Com termination network” (also known simply as a
“termination”) is a Resistor-Capacitor (RC) circuit that must be
connected between the Audio and Ground lines of any Clear-Com
party-line. To ensure correct operation of the external party-line, only
one termination can be installed on any given party-line.
A party-line termination is normally provided by the component
powering the party-line. Although the CCI-22 is not designed to supply
power to an external party-line system, each channel of the CCI-22
features a Clear-Com termination circuit that can be connected to the
party-line by installing a jumper. This termination network is not
normally connected, and should only be connected in the rare case
that the external party-line does not include a termination circuit. An
example of the use of these termination networks is Figure 2-6 on
page 2-6.
If a party-line has more than one termination circuit, it will not null
correctly (see “Rejection Null Adjustment” on page 2-10). The most
common symptom of this is when the line does not null, even though
the “R” null control has been turned all the way counter-clockwise. If
this happens, check all components connected to the party-line that
are capable of providing a termination to be sure that only one
termination is connected to the party-line.
The two termination circuits on the CCI-22 connect to the channel A
and B party-lines; they are enabled and disabled by the jumpers at
JP100 (which controls the termination circuit for channel A) and JP200
(which controls the termination for channel B). JP100 and JP200 are
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