EXP Computer ThinCom PCMCIA Ethernet Modem Adapter - Manual (Page 22)

DIAGNOSTIC DIAGNOSTIC
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DIAGNOSTIC FUNCTION
Setting up for the diagnostic operation: Start the data communication software, then enter the >Terminal Mode= or >Connect Mode=. Set the COM port to match the number use by the modem type >at= then press
ENTER key to check the modem installation.
The Fax/Data Modem supports diagnostic functions defined by ITU (CCITT) V.54 to assist identifying problems of the modem. Basically, these functions loop signals on the local and remote modems to
simulate data communication activities.
These diagnostic functions must be performed under asynchronous operation in non-error-correction mode(normal or direct mode). In command mode, use AT\N1 to enter direct asynchronous mode. To stop
any diagnostic functions in progress, use the escape (+++) sequence to go to command mode, and type AT&T0 .
Local Analog Loopback
This test will loop data from computer to the modem. Use AT&T1 to start the test. CONNECT XXXXX message will be displayed upon the start of the test. After the connection, characters typed on
the computer will be transmitted to the modem and then return to the computer to be displayed on the screen.
Local Analog Loopback with Self-test
Use AT&T8 to initialize this test. The modem will generate a test pattern and looped back and checked by the modem itself. The testing duration is set by the contents of S18. Upon the termination
of the test, it returns the number of detected errors to the computer. Register S16 bit 6 will be set when the test is in progress.
Remote Digital Loopback
Use AT&T6 to initialize this test. The test is to check the connection fault between a local modem and a remote modem. Data is routed from local computer to the local modem, then through the
phone connection to a remote modem. The remote modem then retransmit the data through the same connection back to the local modem, then to the local computer. Before the test, you must establish a
connection with a remote modem. If no connection is made, ERROR message will be returned. The CONNECT XXXX message will be displayed upon the start of the test. After the connection, all characters
you typed on computer will be remote loopbacked and redisplayed on your screen.
Remote Digital Loopback with Self-test
Use AT&T7 to initiate the test, and a test pattern will be looped back and checked by the modem. If no connection is made before the start of the test, ERROR message will be returned. The test
duration is determined by the contents of S18. Upon the termination of the test, it returns the number of detected errors to the computer. Register S16 bit 5 will be set when the test is in progress.
Local Digital Loopback
Before the start of the test, a connection to a remote modem must be established. If no connection, ERROR message will be displayed. Use AT&T3 to start the test. After the start of the test,
characters typed on the remote computer will be routed from the remote modem to the local modem through the connection. The local modem will then return the data to the remote modem, and then
redisplayed on the screen of the remote computer. Register S16 bit 4 will be set when the test is in progress.