3Com 56K manual Testing Using Keyboard Data AT&T6

Testing the Business Modem using AT&Tn 14-7

Testing Using

Keyboard Data

(AT&T6)

1Send AT&M0&N3S14.0=0 to prepare the Business Modem for testing.

This command disables error control, fixes the connection rate at 2400 bps, and makes the Business Modem return to command mode when you type the escape code (+++).

2Establish a connection with the remote device.

3If you haven't already done so, arrange with the remote user to cooperate with the test.

If necessary, set the remote device to acknowledge the remote digital loopback request. For example, older modems need to be set to S16=8.

4Send AT&T6 to the modem. The modem enters remote digital loopback mode, and the MR status light flashes.

5Type a short message. It will be looped back to your modem by the remote device and to your screen for verification. (The remote user will not see your data.)

6Send the escape code, +++, and then AT&T0 to end the test.

Alternatively, you can end the test by sending ATH, ATZ, or ATZ! Be careful, because ATZ and ATZ! reset the Business Modem in addition to ending the test.

If you issue an invalid command, the Business Modem sends an ERROR message. If you set Register S18, the Business Modem automatically ends the test when the test timeout is reached. See the example in the previous section, Stopping a Test for an example of using S18.

Data errors indicate a problem with the remote device or with the phone link.

7Send AT&M4, unless you used a reset command (ATZ or ATZ!).