Com4 (Central Office Module - 4 Circuits) - Comdial DX-80 Installation & Maintenance Manual

COM4 (Central Office Module - 4 Circuits)

The COM4 module is installed in the dedicated position via J1 of the 408M/E. The COM4 interfaces 4 loop-
start CO (Central Office [Telephone Company]) lines. Since one COM4 may be installed in KSU1 and one
COM4 may be installed in KSU2, the DX-80 system CO line capacity may be expanded to interface 16 total
CO lines.
The COM4 module is shipped with four (4) mounting stand-offs used to install the board into the KSU1 or
KSU2. Five RJ11 jacks are provided along the bottom edge of the COM4 module for connection of one
power failure telephone and the four CO lines.
CO lines are terminated at the site by the Telephone Company (RBOC or equivalent) at a point of interface
called the Demarcation (Demarc). When ordering CO lines for the site, request termination on RJ11 type
jacks. Doing so allows CO line(s) to easily be extended to the COM4 RJ11 connector. (One CO line per jack
and connector.)
Each CO line circuit incorporates over-voltage protection, ring detector, loop detector, loop/pulse-dial relay,
current sink circuit, coupling/isolation transformer (impedance 600:600), hybrid circuit, CODEC & filter,
polarity guard circuit and Radio Frequency noise filter.
The fourth CO Line port is equipped with CNG Fax Tone Detection circuitry. When programmed as a "FAX"
line, this circuit will automatically engage the FAX Tone detector. If FAX tone is detected, the call is routed to
the analog port designated as the destination for fax calls.
P7290 IMM
DX-80 I M
NSTALLATION AND
Figure 6: DPM8 (Digital Port Module - 8 Port)
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M
AINTENANCE ANUAL