User`s manual

U.S. Robotics I-modem Command Reference
Troubleshooting • Page 15-3
The I-modem wonÕt accept your directory number (DN)
The I-modem accepts only seven-digit DNs. Try sending the *P command, this time leav-
ing off the area code.
After you dial, the I-modem reports NO CARRIER and then hangs up
¥ You may not have set the correct SPIDs. Send ATI12 and check the Physical Interface
and Data Link Layer entries. Both should read Active. If you have set the wrong SPID
,
Data Link Layer reads Active (Incorrect SPID).
¥ Your I-modem may not be set to use the correct central-ofÞce switch. Often the order
conÞrmation from your local telephone company lists the switch hardware type promi-
nently, when what you are interested in is the switch protocol
. For example, you might
be told that your central- ofÞce switch is a Northern
Telecom DMS-100 running
National ISDN-1
. In this case, you should set the switch type as National ISDN-1.
¥ Set the bus conÞguration as multipoint (AT*M=1), unless your central of
Þce switch is
running A
T&T 5ESS Custom and you have requested point-to-point service.
¥ 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 I-modem (send ATZ) after you Þnish the call.