COMSTAT
The COMSTAT
structure contains information about a communications device. This structure is
filled by the ClearCommError
typedef struct _COMSTAT { // cst
DWORD
fCtsHold : 1; // Tx waiting for CTS
signal
DWORD
fDsrHold : 1; // Tx waiting for DSR
signal
DWORD
fRlsdHold : 1; // Tx waiting for RLSD
signal
DWORD
fXoffHold : 1; // Tx waiting, XOFF char
rec'd
DWORD
fXoffSent : 1; // Tx waiting, XOFF char
sent
DWORD fEof
: 1; // EOF character sent
DWORD
fTxim : 1; // character waiting for
Tx
DWORD
fReserved : 25; // reserved
DWORD
cbInQue; // bytes in input buffer
DWORD
cbOutQue; // bytes in output buffer
} COMSTAT, *LPCOMSTAT;
Members
fCtsHold
Specifies
whether transmission is waiting for the CTS (clear-to-send) signal to be sent.
If this member is TRUE, transmission is waiting.
fDsrHold
Specifies
whether transmission is waiting for the DSR (data-set-ready) signal to be sent.
If this member is TRUE, transmission is waiting.
fRlsdHold
Specifies
whether transmission is waiting for the RLSD (receive-line-signal-detect)
signal to be sent. If this member is TRUE, transmission is waiting.
fXoffHold
Specifies
whether transmission is waiting because the XOFF character was received. If
this member is TRUE, transmission is waiting.
fXoffSent
Specifies
whether transmission is waiting because the XOFF character was transmitted. If
this member is TRUE, transmission is waiting. Transmission halts when the XOFF
character is transmitted to a system that takes the next character as XON,
regardless of the actual character.
fEof
Specifies
whether the end-of-file (EOF) character has been received. If this member is
TRUE, the EOF character has been received.
fTxim
If this
member is TRUE, there is a character queued for transmission that has come to
the communications device by way of the TransmitCommChar
fReserved
Reserved; do
not use.
cbInQue
Specifies the
number of bytes received by the serial provider but not yet read by a ReadFile
cbOutQue
Specifies the
number of bytes of user data remaining to be transmitted for all write
operations. This value will be zero for a nonoverlapped write.
See Also