ioctl12.hlp (Topic list)
Important Notice
The pages on this site contain documentation for very old MS-DOS software, purely for historical purposes. If you're looking for up-to-date documentation, particularly for programming, you should not rely on the information found here, as it will be woefully out of date.
ASYNC_GETMODEMOUTPUT (1.2)
                                                      Up Next Previous
────────────────────────────────────────────────────────────────────────────
 
#define INCL_DOSDEVIOCTL
 
USHORT DosDevIOCtl(pbCtrlSignals, 0L, 0x0066, 0x0001, hDevice)
PBYTE pbCtrlSignals;    /* pointer to variable for control signals */
HFILE hDevice;          /* device handle                           */
 
The ASYNC_GETMODEMOUTPUT function retrieves the modem-control output signals
for the specified device.
 
Parameter      Description
────────────────────────────────────────────────────────────────────────────
 
pbCtrlSignals  Points to the variable that receives the modem-control
               signals. This variable can be one or both of the following
               values:
 
               Value   Meaning
               ─────────────────────────────────────────────────────────────
               DTR_ON  Data-terminal-ready (DTR) signal is on. If not given,
                       the signal is off.
 
               RTS_ON  Request-to-send (RTS) signal is on. If not given, the
                       signal is off.
 
hDevice        Identifies the serial device that receives the device-control
               function. The handle must have been created previously by
               using the DosOpen function.
 
Return Value
 
The return value is zero if the function is successful or an error value if
an error occurs.
 
See Also
 
DosOpen, ASYNC_GETMODEMINPUT, ASYNC_SETMODEMCTRL
 
                                      ♦