3Com 56K manual Double characters are appearing on your monitor

Problems That Occur Before Connecting 15-3

Double characters are appearing on your monitor

This is a signal that both the Business Modem's local echo and your software's local echo are on.

Type the command to turn off your online echo (ATF1) or turn your communications software's local echo off (refer to your software's documentation).

After you dial, the Business Modem reports NO CARRIER and then hangs up

■Try increasing S7 and decreasing S9 to allow more time for the connection.

■Try calling a different device. If you are trying to connect to an older modem at 2400 bps or less, it may not support error control. Try sending AT&M0, and then try the call again. Reset the Business Modem (send ATZ) after you finish the call.

Hear ringing but the Business Modem won't answer

■Look at the TR LED to make sure that your terminal or computer is sending a DTR signal via the EIA-232 interface.

■Send ATI4 to the Business Modem and check that S0 is set to a value higher than 0.

■Set &F1 and S0=1, then try again.

The Business Modem acts as though a data link has been established, but no call was received,

Carrier Detect (CD) may be overridden (with &C0), but your system may require that the override be turned OFF (with &C1). Review your communications software manual to see what CD operations are required.

The Business Modem behaves as if <Enter> were pressed when you don't press any keys

Your software may be misreading signals from the Business Modem when the Business Modem sends a Carriage Return and a Line Feed before and after the RING and CONNECT messages. Sending the Quiet mode command, ATQ1, should solve the problem.