Direct Modem Connection

Troubleshooting a Direct Modem Connection
The direct-modem connection requires that the communication between the communications port and the modem work smoothly. Given the wide variety of modems and computers installed, getting the settings correct may at times require some extra attention. This section includes points to look at if the Direct Modem connection fails to dial and synchronize with the NIST timeserver.

Modem Fails to Dial

The phone line is not configured for outbound dialing.

Check to see that:
* No prefix or account code is required to dial an outside line.
* The phone line or extension in use is restricted from dialing a long distance number.
Tip: Test the line by taking the phone line from the modem, plug it into a regular telephone and dial the NIST at 1-303-494-4774. The NIST modem should answer the call.

Turn handshaking on or off on the Direct Modem Connection screen. Some modems require that handshaking be set to allow the modem to dial. Settings can be first tested by using the Modem Test Screen.

Try turning the RTS and DTR enable on or off, adjust both the Type Handshake to None or RTS.

Try a different Attention string. If the Attention string is invalid for the modem in use, then the modem will not be able to continue. Try the different Attention strings available in the Templates on the Direct Modem Connection form.

Modem Dials NIST but Doesn't Synchronize

Try turning RTS handshaking off (if it is on). The modem might be waiting for a change in state from the communication port that never comes.

Try turning off Flow Control and/or MNP data compression in the modem. An Attention string of AT&K0%C0 will often do both on many modems. Try