Instruction manual

Hardware Overview
025-9416 23
Trunk B
Socket
Trunk A
Socket
Dual Trunk
Matrix Card
Selected
Line Type
Bottom Edge
Connector
J4
J3
J1
J2
DID
Figure 6. Dual Trunk Interface Matrix Cards
For Simplified schematic diagrams of the four telco trunk types serviced by the matrix card, see
“Configuration Diagrams” in Section 11.
External RS-232 Ports
Two 9-pin serial ports on the rear of the trunk card provide interface to an alphanumeric input
device. The Model 640 supports the TAP (Telocator alphanumeric protocol) for alphanumeric
display paging. A paging entry station can be directly connected to the DB-9 ports to enable an
operator to manually enter alphanumeric pages into the paging terminal.
Note: Each RS-232 port that is active replaces a trunk. As a result, the total number of
inputs always remains 4 (if a second trunk card is installed). For example, if one TAP
port is used, then only 3 trunks remain available for telco paging activity.
Modem Interfaces
A DUART (U15) on each dual trunk board interfaces the standard modems (U21, U22) with the
peripheral board processor. It also provides some general purpose I/O functions for the processor.
The modem interfaces may be disabled in order to enable RS-232 alpha interfaces through stan-
dard rear panel DB-9 connectors.
Audio Level Adjustments
Four audio level adjustment are located on the front of the dual trunk interface for each trunk.
Figure 7 shows the front panel of the Model 640. Each trunk has three pots and one switch that
define the audio levels. In addition, three front-panel LEDs identify operation of each trunk (12
total).
See Section 6 for detailed adjustment procedures.