Dpm8 (Digital Port Module - 8 Circuits) - Comdial DX-80 Installation & Maintenance Manual

APM4's may be installed on 408M/E-J5 (standard in KSU1:408M-J5), 408M/E-J2 or 408M/E-J3. (Note it is
not possible to install an APM4 on both J2 and J3 on any one 408.)
When an APM4 is installed via J2 or J3, they take the place of DPM8 modules that might be installed in
those locations. Therefore APM4 modules installed using J2 or J3 will reduce the total number of Digital Port
Modules (DPM8) possible.

DPM8 (Digital Port Module - 8 Circuits)

The DPM8 module expands the DX-80 system capacity of digital ports DET (Digital Executive Telephones)
and DSS Consoles. Each digital port is comprised of a proprietary octal ASIC (Application Specific
Integrated Circuit) transceiver. There are three data channels in operation at each digital port via the octal
transceiver. One channel is used for call processing control of digital terminal functions/operations and two
channels are used for the digital voice channel requirements. The DPM8 is controlled directly from the
408M/E (therefore there is no heartbeat LED located on the DPM8.)
Each digital station interface is protected against circuit wiring shorts by an over-current protection
Polyswitch. The digital station circuit requires only one cable pair to operate and is not polarity sensitive.
Physical connection of digital port terminals (DET and DSS) to the DPM8 module is made through
convenient RJ-11 connectors along the bottom edge of the module. Depending on the site installation
requirements the installer may choose to route terminal (station) wiring directly into the KSU cabinet and
connect the individual terminal cables to the RJ-11 extension port desired via field crimped RJ-11 plugs.
This streamlined installation capability can eliminate the traditional cross-connect field hence reduce costs of
installation. (Be advised that we do not recommend this practice since it is inherently difficult to
service. When using field-crimping tools, use quality tools. Cheap tools yield bad connections.)
P7290 IMM
DX-80 I
NSTALLATION AND
Figure 5: APM4 (Analog Port Module - 4 Circuits)
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M M
AINTENANCE ANUAL