Chapter 6 - Testing Your Modem
Note: The &T4 command must be set on the remote modem to run this test.
3.Type the Escape Sequence (+++AT<CR> or <BREAK>AT<CR>) which brings your modem into Command mode, while still maintaining the connection with the remote modem.
4.Type ATU2 and hit ENTER. The local modem responds to this command by transmitting an unscrambled marking signal, which causes the remote modem to place itself in Digital Loopback mode. Then the local modem exits Command mode and enters pseudo
5.Type data from your keyboard. For this test, typing multiple upper case "U" characters is a good way to send an alternating test pattern of ones and zeros. The data received by the remote modem will enter its analog receiver, be converted to digital data, be reconverted into analog, and then looped through its transmitter back to the local modem. Your modem passes this test if the data entered from the local keyboard is the same as the data received on your monitor.
Figure 6-3. Digital Loopback Test (remote/automatic)
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