Specifications

OVERVIEW DX-120 Installation and Maintenance Manual
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408E - KSU2 Component (continued)
• 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 automatically engages the FAX tone detector. If FAX tone is detected, the system routes the
call 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-120 to support auxiliary office
equipment such as fax machines, PC/FAX modems, and analog telephones (single line telephones). The APM4
generates -30VDC and 20-25Hz, 50V square wave ringing for operation.
APM4 (Analog Port Module - 4 Circuits)
• 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.
IMPORTANT
Pulse (rotary-dial) telephones/equipment are not supported.
APM4 - Analog Port Module (continued on next page)