Apm4 (Analog Port Module - 4 Circuits) - Comdial DX-80 Installation & Maintenance Manual

The 408E is equipped with a Heartbeat LED that indicates processing activity on the PCB. (The 408E
peripheral processor is operating when the Heartbeat LED is flashing.) The KSU2 operation LED (located
next to the power switch) is tied to the 408E Heartbeat LED. Therefore, when the LED next to the power
switch is flashing, the 408E is active.
The KSU2-408E connections are almost identical to those on the 408M (KSU1). The exception is the long
shielded cable used to connect KSU2 to the CPM inside of KSU1. (Also notice: that there is no standard
APM4 installed inside of KSU2.)
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.
Each digital port (connects to Digital Executive Telephones and DSS Consoles) is comprised of a
proprietary octal ASIC (Application Specific Integrated Circuit) transceiver. There are three data channels in
operation at each extension 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.
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 extension terminals, power failure telephones and CO lines to the 408M
module is made through convenient RJ-11 connectors along the bottom edge of the module.

APM4 (Analog Port Module - 4 Circuits)

The APM4 provides four separate analog device ports. This allows the DX-80 to support auxiliary office
equipment found on the business premises such as fax machines, PC/Mac modems and analog telephones
(single line telephones). The APM4 generates -30VDC and 20-25Hz, 50V square wave ringing for operation.
The APM4 is equipped with a Heartbeat LED that indicates processing activity on the PCB. (The APM4
peripheral processor is operating when the Heartbeat LED is flashing.)
The APM4 provides DTMF receivers for each analog port. Ancillary analog devices connected to APM4
analog ports must generate DTMF signaling. (Pulse dial (rotary-dial) telephones/equipment are not
supported.) All connections are via RJ-11 connectors along the bottom edge of the module. KSU1 is
delivered with one APM4 installed on Ribbon Connector J5 as standard equipment.
P7290 IMM
DX-80 I M
NSTALLATION AND AINTENANCE
Figure 4: KSU2 (Key Service Unit 2)
1-8
M
ANUAL