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What if the modem will dial, but communications fail when using UPS hardware?

  • If you are experiencing a communications failure, take the following steps:

    1. Make sure the Dial Prefix setting is correct. If you hear the modem dialing but never hear the modem "squealing" (signifying that a modem connection is being established), chances are that the Dial Prefix setting is incorrect. If the problem occurs during registration, verify that the Dial Prefix setting is correct. The default prefix 9 should be removed if dialing 9 for an outside line is not necessary.
    2. Find out whether the Baud Rate field is set to a value higher than what your modem or computer is capable of. The recommended maximum baud rate setting is 9600. If a communications problem exists when using a high-speed modem, dropping the baud rate value to 9600 may resolve the problem. Also note: some computers will not support external modems set to a baud rate faster than 9600.
    3. Try selecting Hayes® Compatible Modem in the Modem field. The Hayes Compatible Modem setting has been found to work with most modems, regardless of the modem's make and model. If experiencing a communications problem, always try this setting.
    4. Use the following modem initialization string if you are using a US Robotics® Sportster modem that is faster than 14,400 baud (14. 4kbps): AT&F&B1&H1&R2&A3&K3X4.

    Note: Sometimes the UPS mainframes and communications equipment are overloaded, resulting in time-outs and possibly failed communications requests. Be sure to repeat the communications attempt several times over a period of time. If problems persist, call UPS.