MT3334HD8 User Guide
Introduction
Each time you power up the MT3334HD8, it performs an automatic
In a loopback test, data from your computer loops through the circuits of your modem and/or a remote modem before it appears on your monitor. When the loop has been completed, the data on your PC’s monitor should match the original data.
The local analog loopback test allows you to verify that the modem’s transmitter and receiver circuits are functioning properly.
The local digital loopback allows you to verify that the local computer or terminal, the two modems, and the transmission line between them are functioning properly.
The remote digital loopback test allows you to verify that the remote computer or terminal, the remote modem, the serial ports, the telephone line, and the local modem are functioning properly.
Note: All loopback tests operate at all speeds except 300 bps.
Other tests are initiated with the MultiModemManager software, as explained in the MultiModemManager Owner's Manual.
Local Analog Loopback Test (V.54 Loop 3)
In this test, data from your computer or terminal is sent to your modem’s transmitter, converted into analog form, looped back to the modem’s receiver, converted into digital form, and then sent to your monitor for verification. No connection to the phone line is required. See Figure 2.
Computer or Terminal | Local MultiModem |
UUUUU
UUUUU
Digital Analog
Type ATU0 or ATU1 in terminal mode; hit ENTER.
Figure 2. Local analog loopback test.
Test procedure
1.Connect the modem to your computer. Using your communication software, set the desired baud rate.
2.Type ATU or ATU0 and press ENTER. This places your modem in analog loopback mode in the originate mode. A CONNECT message should appear on your display. The modem is now out of command mode and in a
54 | CommPlete Communications Server |