Comtrol Multiport Modems Windows XP - Manual (Page 22)

22 Installing the Device Driver
Configuring Port Properties
b. Timeout on transmit data on port close: Use this droplist to select the length
of time to wait for data to clear the transmit buffer after a host application
has closed the port. This is typically used with peripheral devices such as
printers, to give the data sufficient time to flush through the system.
c. Map CD to DSR: This option is used in installations where there is no
connection to the port’s DSR input. Select this check box to cause the CD
input to appear as DSR to the host application, and to perform hardware
handshaking with CD rather than DSR. This is ignored if flow control is
not enabled via IOCTL_SERIAL_SET_HANDFLOW.
d. Map 2 stop bits to 1: If the application you use is hard-coded to use two stop
bits and you receive framing errors, select this check box to map 2 stop bits
to 1 bit. Otherwise, leave this box unchecked.
e. Wait on physical transmission before completing write: This option forces all
write packets to wait until the transmit data has physically completed the
transmission before returning completion to the host application. The
default mode (check box not selected) is to buffer the data in the transmit
hardware buffer, and return completion as soon as the packet is in the
buffer.
f. Emulate modem hardware RING signal: Select this check box to emulate the
ring indicator signal. If this feature is enabled, the driver monitors the
data stream and outputs a software RI whenever the RING AT command
is received.
g. Clone: If this check box is not selected, changes apply to the selected port
only. If this check box is selected, changes apply to all ports on this board.
h. Defaults: Select this to return to the driver default values.
3. Select the OK button after configuring this port or select the Clone check box
to set all of the port to these characteristics.