Port Specifications

The following tables provides interface specifications for System 25 line and trunk port circuits: supported by System 25:

DATA TERMINAL PORTS (Note)

STATION TYPE

 

CIRCUIT PACK

DATA TERMINAL SPECIFICATIONS

 

 

 

 

 

 

 

 

EIA RS-232 Device Via

 

Data Line

RS-232 device must furnish signals on ADU

ADU

 

(TN726)

pins 2 (TD) and 20 (DTR) and ground on

 

 

 

either pin 1 or 7. The ADU furnishes

 

 

 

signals on pins 3 (RD) and 8 (CD). The CD

 

 

 

signal is also tied to pins 5 (CTS) and 6

 

 

 

(DSR). Some data terminals may require

 

 

 

auxiliary power when used with a Z13A1,

 

 

 

Z3A2, or Z3A4 ADU (the Z3A5 always

 

 

 

requires local power.) ADUs require 7 volts

 

 

 

on pin 20 (DTR) to operate properly. The

 

 

 

following table lists data terminals that

 

 

 

have been tested and are known to operate

 

 

 

properly without auxiliary power.

 

 

 

 

Note: Refer to

Cable Distance Limitations for supported data rates.

5 - 1 0

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AT&T AT&T manual Data Terminal Ports Note, Station Type Circuit Pack Data Terminal Specifications