nf-winbase-getcommmodemstatus.md

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NF:winbase.GetCommModemStatus	GetCommModemStatus function (winbase.h)	Retrieves the modem control-register values.	GetCommModemStatus GetCommModemStatus function MS_CTS_ON MS_DSR_ON MS_RING_ON MS_RLSD_ON _win32_getcommmodemstatus base.getcommmodemstatus winbase/GetCommModemStatus	base\getcommmodemstatus.htm	base	937bb623-d02d-452e-a8a2-21d9a6c5cac0	12/05/2018	GetCommModemStatus, GetCommModemStatus function, MS_CTS_ON, MS_DSR_ON, MS_RING_ON, MS_RLSD_ON, _win32_getcommmodemstatus, base.getcommmodemstatus, winbase/GetCommModemStatus	winbase.h	Windows.h	Windows	Windows XP [desktop apps \| UWP apps]	Windows Server 2003 [desktop apps \| UWP apps]										Kernel32.lib	Kernel32.dll		Windows			19H1	GetCommModemStatus winbase/GetCommModemStatus	c++	APIRef kbSyntax	DllExport	Kernel32.dll API-MS-Win-Core-comm-l1-1-0.dll KernelBase.dll API-MS-Win-DownLevel-Kernel32-l1-1-0.dll MinKernelBase.dll	GetCommModemStatus

GetCommModemStatus function

-description

Retrieves the modem control-register values.

-parameters

-param hFile [in]

A handle to the communications device. The CreateFile function returns this handle.

-param lpModemStat [out]

A pointer to a variable that receives the current state of the modem control-register values. This parameter can be one or more of the following values.

Value	Meaning
MS_CTS_ON 0x0010	The CTS (clear-to-send) signal is on.
MS_DSR_ON 0x0020	The DSR (data-set-ready) signal is on.
MS_RING_ON 0x0040	The ring indicator signal is on.
MS_RLSD_ON 0x0080	The RLSD (receive-line-signal-detect) signal is on.

-returns

If the function succeeds, the return value is nonzero.

If the function fails, the return value is zero. To get extended error information, call GetLastError.

-remarks

The GetCommModemStatus function is useful when you are using the WaitCommEvent function to monitor the CTS, RLSD, DSR, or ring indicator signals. To detect when these signals change state, use WaitCommEvent and then use GetCommModemStatus to determine the state after a change occurs.

The function fails if the hardware does not support the control-register values.

-see-also

Communications Functions

Communications Resources

CreateFile

WaitCommEvent