Configuring The Modem Connection - Digi PortServer II User Manual

• Many modems have external or internal jumpers that override the normal
operation of DTR, DCD, RTS and CTS. Check the settings of these jumpers on
your modem by referring to your modem manual.
• You can watch the LEDs on the PortServer II front panel to monitor correct
modem operation. In particular, verify that DCD is off when the modem is not
connected. Verify that the modem does not answer a call when DTR is low, and
hangs up when DTR is dropped.

Configuring the Modem Connection

1. Set the relevant PortServer II serial port to the highest speed that the modem can
accept without data corruption, by entering the following command:
set line baud=<speed> range=<ports> [options]
<speed> is the baud rate of the serial port, which can only be set to certain legal
values (refer to set line in the Command Reference Guide). <ports> speci-
fies the port(s) you are setting. [options] are control and parity settings and
must correspond to your modem's settings.
For example, to set serial port 4 to 2400 baud and tell it to ignore parity errors,
enter:
set line baud=2400 range=4 error=ignore
Note: Remember that this command sets the PortServer II-to-Modem connec-
tion, not the speed at which the modem communicates over the telephone
lines. If you are uncertain of the best value, we suggest you try the default
setting of 9600 baud. If this does not allow reliable data transfer, lower
this value until you obtain satisfactory results. If the default setting allows
reliable transfer, increase the value until you obtain the highest setting
that allows reliable transfer.
2. If you have not already done so, set the serial port for the modem device type, by
entering:
set port dev=<modem_type> range=<ports>
<modem_type> may be mio for a bidirectional modem, min for an input-only
modem, or mout for an output-only modem. <ports> specifies the port(s) you
are setting. For example, to use a bidirectional modem on port 4, enter:
set port dev=mio range=4
90030500B Configuring Modem Connections Page 127