First, make certain that you are not including any hyphens or spaces in the ATD
dialing string. For example, you should be entering
ATD9544305811.
After verifying that you have properly entered the dialing string, if the modem
still will not place an outbound call, you may have to enter the phone number
into the modem before performing an Over-the-Air Provision. Please see sections
5.3 through 5.6.
5.0 Troubleshooting
In this section, you will find important information relating to the setup and diagnosis of
your modem. If you are having trouble communicating with the modem, please read this
"Troubleshooting"
section and the
"Frequently Asked Questions"
section 11.0 in full. If,
after reviewing these sections, you are still having problems connecting, call our
Technical Support line at: 954-430-5811 for more assistance. Toll charges may apply.
5.1 Helpful Hints
·Only assign one device to any given COM port on your system.
·The Land-Cellular CDM819i and CDM820i data modems have a default COM port
speed of 57600bps. This is the data rate at which your modem connects to your computer.
The modem's COM port speed can be lowered to 300bps or raised to 115.2Kbps. As this
setting adjusts the communications speed that the modem utilizes to speak to the
computer, altering this parameter must be performed in a very specific way. Otherwise,
you may lose communication with the modem. To alter the default speed of 57600bps,
first, connect via your terminal emulation software (settings: 57600bps, 8, N, 1,
Hardware). Now, you may issue the
AT+IPR
command to query or change the default
speed. After adjusting the port speed, disconnect from the modem and reconnect using
the new data rate. Refer to the
"Frequently Asked Questions"
section 11.0 for more
information pertaining to the
AT+IPR
command.
·Make certain the serial cable is firmly connected to an enabled COM port with no
hardware resource conflicts. Make sure that you have properly added the "Standard
19200 bps Modem" to your system using the
"Setting Up Your Modem"
section 2.2
above. Also, check to see if you have an infrared (IR) port assigned to your modem's
COM port. Disable it if you are not using this function. Often, an IR port can interfere
with the COM port even after you successfully connect. Device Manage r may indicate
that there is no conflict between the two, but disabling the IR port may still help.
·If your system's COM port appears to be locked, you may have to shut down and reboot
your system.
·Do not use "Disable Call Waiting" (commonly referred to as *70) when configuring
Dialing Properties.
·Make certain that you are using the proper RS-232 serial cable. For most applications,
you must use a straight-through RS-232 serial cable. For certain types of equipment, you
may be required to use a null modem cable. For more information on this, refer to the
FAQ section 11.11 titled
"When Do I Need A Null Modem Cable?"
.
5.2 Diagnosing COM Port Problems Using Hyperterminal
