Digital Loopback Test/V.54 Loop 2 (Loc/Man) - Multitech MMH900 User Manual

I.3 Digital Loopback Test/V.54 Loop 2 (Loc/Man)
In this test, your modem must be On-Line with another modem that can
respond to a request for Digital Loopback, such as another MMH2834.
The Digital Loopback Test is an on-line test that loops data sent from one
modem across the phone line to another modem, then back to the first
modem. See Figure I-2.
There are two ways to put a modem into Digital Loopback mode.
1. Locally or Manually, described here in section I.3.
2. Remotely or Automatically, see section I.4.
Note: The Digital Loopback Tests can only be used with the modem in
Normal mode (error correction off).
Computer or Terminal Local MultiModem
Digital Analog
Type AT in Terminal mode; hit
ENTER; dial remote modem;
establish On-line mode; enter
escape sequence; type ATU3
and hit ENTER
Figure I-2. Digital Loopback Test (local/ manual)
In this test the local modem is placed in Digital Loopback mode. Data is
entered and transmitted from the remote modem (which is not in digital
loopback mode), sent across the phone line to the local modem and
looped back to the remote modem.
The test procedure is as follows:
1. Go into Terminal mode. Type AT and hit ENTER; you should get an
OK message.
2. Dial the remote modem by entering the Dial command and the phone
number, to establish On-line mode.
3. Type the Escape Sequence (+++AT<CR> or <BREAK>AT<CR>)
which brings your modem into Command mode, while still
Appendix I - Testing Your MMH 2834
Remote MultiModem Computer or Terminal
UUUUU
UUUUU
Analog Digital
151