Instruction manual

Hardware Overview
025-9416 29
PARALLEL PRINTER CARD
The parallel printer option (Part No. 950-9758) enables the Model 640 to print the system log
data in real-time. When the printer card is installed in either expansion slot (items #9 and #10,
Figure 2), a printer can be connected to the DB-25 that is exposed through the rear of the chassis.
Any standard serial printer cable works.
DUAL DIAL CLICK CARD
The dual dial click decoder option (Part No. 702-9119) enables the Model 640 to process digits
dialed by rotary telephones. Dial clicks are different from dial pulses. The Model 640 can decode
dial pulses without the optional dial click decoder board.
DUAL MF DECODER CARD
The dual multifrequency decoder option (Part No. 702-9197) allows the Model 640 to accept MF
digit feed from DID and E&M 2- or 4-wire trunks. MF is a dual-tone signaling format similar to
standard touch-tone (DTMF).
FRONT PANEL LEDS
The Model 640 has 18 red LEDs on its front panel. Many of the LEDs serve the same function,
but for different trunks. Refer to Figure 7 for the location of each LED. Table 5 describes the
operation of each LED.
Note: The Model 640 has four LINE, ANS, and ACT LEDs - each trunk has its own set. They
operate identically for each trunk.