Digital Loopback Test (Rem/Auto)(Sync Mode) - Multitech MMH900 User Manual

I.8 Digital Loopback Test (Rem/Auto)(Sync
Mode)
This test must be run when you have a data connection with another
modem. In this test, data is passed to the remote modem and is looped
back to the local modem (as if an ATU2 command was issued in
Asynchronous test mode), as shown in Figure I-6. This lets you test the
local and remote modem's transmit and receive circuits, as well as your
computer's serial COM port and the phone lines. If the test results in a
mismatch of entered/received data (multiple upper case "U" characters
in Figure I-6), the Local Analog Loopback Test should be performed on
both the remote and local modems. If that test is successful, the problem
format is sync. Sync mode is set usng the $M(Sync) command. Once
you receive an OK message from your modem (if responses are
enabled), the local modem is placed in Digital Loopback mode.
Local MultiModem
Computer or Terminal
UUUUU
UUUUU
Digital
DIP-Switch #9
DOWN;
Answ/Orig
Switch Toggled
to Answ
position when
On-line
Figure I-6. Digital Loopback Test (remote/automatic) (Synchronous
Appendix I - Testing Your MMH 2834
Remote MultiModem
Analog Analog Digital
&T4 Command
Mode)
Computer or Terminal
158