User's Guide
Table Of Contents
- Table of Contents
- About This Document
- 1. Introduction
- 2. Installation
- 3. Configuration and Operation
- 4. Troubleshooting
- A. AT Command Set
- B. Dial Modifiers
- C. S-Registers
- D. Isolating Problems Using Loopback Data Tests
- E. Quick-Reference Summaries
- Glossary
- Index
8400B Plus Data Module User’s Guide
555-020-709
Issue 2
November 1996
Isolating Problems Using Loopback Data Tests
D-5
Local Loopback Test with Self-Test
Local Loopback Test with Self-Test
This test evaluates the data module’s transmit and receive circuitry by having
the data module generate test characters internally. At the end of the test, the
8400B Plus Data Module displays a three-digit number indicating the number of
errors that occurred during the test. If you receive an error count other than
zero, you may have a defective data module. Call the Lucent Technologies
Technical Service Center at 1 800 242-2121.
NOTE:
Initiating this test disconnects a call if one is in progress.
Figure D-3. Local Loopback Test with Self-Test
Local DTE
8400B Plus
Transmitter
Test Circuit
S
W
I
T
C
H
Receiver
020709_2.book Page 5 Friday, April 23, 1999 5:39 AM