Filter
Top Products
58
Chapter 5 - Testing the Modem
ATU1 and hit ENTER to place the modem in Analog Loopback mode, in
the Answer mode. Then repeat step 3.
5. When testing is completed, you may exit Answer mode by entering an
Escape Sequence (+++AT<CR> or <BREAK>AT<CR>), which returns
the modem to Command mode.
6. Your modem passes this test if the data entered from your keyboard are
the same as the data received on your monitor. If different data is
appearing on your monitor, your modem is probably causing the
problem, although it could also be your computer. If your modem
passes this test, but you are receiving errors while On-line, the remote
modem or the phone line could be at fault.
5.2 Digital Loopback Test/V.54 Loop 2 (Local/Manual)
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 5-2.
There are two ways to put a modem into Digital Loopback mode.
1. Locally or Manually, described here in section 5.2.
2. Remotely or Automatically, see section 5.3.
Note: Loopback tests operate at all speeds except 300 bps. Disable error
correction (&E0&W0<CR>) before engaging in loopback tests.
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.