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.
5-10