Comtrol API (6508) for the MS-DOS User Manual
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API Functions
aaChangeModemState
aaChangeModemState
Changes the state of modem output lines.
aaChangeModemState(Dev,
RTSS
tate,
DTRS
tate)
int Dev
Device number
int
RTSS
tate
State of
RTS
line:
ON
,
OFF
, or
NOCHANGE
int
DTRS
tate
State of
DTR
line:
ON
,
OFF
, or
NOCHANGE
int:
NO_ERR
if successful
ERR_DEV
if device out of range
Function
Purpose
Call
Return
aaClose
Closes a device.
aaClose(Dev,ModemCtl)
int Dev
Device number
unsigned char ModemCtl
Modem control lines to turn
OFF
, can be
COM_MDM_RTS
or
COM_MDM_DTR
. If the flag
is not set the state of the
modem line is not changed.
int:
NO_ERR
if successful
ERR_DEV
if device number out of range
ERR_MDMCTL
if invalid modem control flag
ERR_NOTOPEN
if device not open
This function waits for the device’s transmit buffer to
drain before completing the close. The maximum wait
time defaults to
CLOSE_TBEDLY
, but can be changed
with the aaSetCloseDelay() function.
This function disables and enables interrupts.
Function
Purpose
Call
Return
Comments
Warning