pulse dialing, the line may not be able to accept tone-dialed calls. Select Pulse dialing in your software, or make sure the software dialing prefix is ATDP (for pulse dialing).

Make sure your communications software and modem are configured for the same COM port.

Make sure your modem has hung up from the previous call. Select Hang Up in your software; or type ATH in terminal mode.

Problem: The modem can connect to some modems, but not to others.

Solution: A remote modem does not respond because of the extended negotiation process by which modems determine the best common connection between them. If this is the case, you may have to disable part or all of the negotiation process. In the following table, “protocol” means error correction and data compression.

To force different communication speeds

Type these AT

 

commands and

 

press Enter

Negotiate speed and protocol (default setting)

AT &F

To force protocol

AT \N3

Dualmode (V.90 or V.92)—56000 bps

AT+MS=V92,1

V92 only (disable V.90)—56000 bps

AT+MS=V92,0

V.90 only (disable V.92)—56000 bps

AT+MS=V90,0

Disable both 56K and autorate on V.34—33600 bps

AT+MS=V34,1

V.34—33600 bps

AT+MS=V34,0

V.32bis—14400 bps

AT+MS=V32B,0

V.32—9600 bps

AT+MS=V32,0

2400 bps

AT+MS=V22B,0

1200 bps

AT+MS=V22,0

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