Isolating Problems Using Loopback Data Tests
D-10 Issue 2 November 1996
Loop-Around Data Test
Arrangement
The 8400B Plus Data Module Loop-Around Data Test Arrangement provides a
simple mechanism that can be installed on a DEFINITY Communications
System, to isolate Digital Communications Protocol (DCP) data problems. In the
Loop-Around Data Test Arrangement one or more 8400B Plus Data Modules
are set up for auto-answer, and have the received data lead looped around to
the transmit data lead on the data module’s EIA interface. A user can then dial
up, and see whether data typed in at the local station is echoed back. A typical
use for this would be a user who calls the Help Desk with the complaint that
he/she cannot access a local host. The user can be instructed to utilize the
Loop-Around Data Test Arrangement (see Figure D-6).
Figure D-6. Local Configuration, Using Loop-Around Data Test
Arrangement
Terminal
or
PC
Data Module,
PC/PBX,
or
Asynchronous
Data Unit
8400B Plus
Host
Data Module
Loopback
Plug
DCP
or ADU
Loop-Around Data
Test Arrangement
Two-Wire
DEFINITY
Communications
System
G3V2
or later
