COMMPROP

The COMMPROP structure is used by the GetCommProperties function to return information about a given communications driver.

typedef struct _COMMPROP { // cmmp

WORD wPacketLength; // packet size, in bytes

WORD wPacketVersion; // packet version

DWORD dwServiceMask; // services implemented

DWORD dwReserved1; // reserved

DWORD dwMaxTxQueue; // max Tx bufsize, in bytes

DWORD dwMaxRxQueue; // max Rx bufsize, in bytes

DWORD dwMaxBaud; // max baud rate, in bps

DWORD dwProvSubType; // specific provider type

DWORD dwProvCapabilities; // capabilities supported

DWORD dwSettableParams; // changable parameters

DWORD dwSettableBaud; // allowable baud rates

WORD wSettableData; // allowable byte sizes

WORD wSettableStopParity; // stop bits/parity allowed

DWORD dwCurrentTxQueue; // Tx buffer size, in bytes

DWORD dwCurrentRxQueue; // Rx buffer size, in bytes

DWORD dwProvSpec1; // provider-specific data

DWORD dwProvSpec2; // provider-specific data

WCHAR wcProvChar[1]; // provider-specific data

} COMMPROP;

Members

wPacketLength

Specifies the size, in bytes, of the entire data packet, regardless of the amount of data requested.

wPacketVersion

Specifies the version of the structure.

dwServiceMask

Specifies a bitmask indicating which services are implemented by this provider. The SP_SERIALCOMM value is always specified for communications providers, including modem providers.

dwReserved1

Reserved; do not use.

dwMaxTxQueue

Specifies the maximum size, in bytes, of the driver's internal output buffer. A value of zero indicates that no maximum value is imposed by the serial provider.

dwMaxRxQueue

Specifies the maximum size, in bytes, of the driver's internal input buffer. A value of zero indicates that no maximum value is imposed by the serial provider.

dwMaxBaud

Specifies the maximum allowable baud rate, in bits per second (bps). This member can be one of the following values:

dwProvSubType

Specifies the specific communications provider type:

dwProvCapabilities

Specifies a bitmask indicating the capabilities offered by the provider. This member can be one of the following values:

dwSettableParams

Specifies a bitmask indicating the communications parameter that can be changed. This member can be one of the following values:

dwSettableBaud

Specifies a bitmask indicating the baud rates that can be used. For values, see the dwMaxBaud member.

wSettableData

Specifies a bitmask indicating the number of data bits that can be set. This member can be one of the following values:

wSettableStopParity

Specifies a bitmask indicating the stop bit and parity settings that can be selected. This member can be one of the following values:

dwCurrentTxQueue

Specifies the size, in bytes, of the driver's internal output buffer. A value of zero indicates that the value is unavailable.

dwCurrentRxQueue

Specifies the size, in bytes, of the driver's internal input buffer. A value of zero indicates that the value is unavailable.

dwProvSpec1

Specifies provider-specific data. Applications should ignore this member unless they have detailed information about the format of the data required by the provider.

Set this member to COMMPROP_INITIALIZED before calling the GetCommProperties function to indicate that the wPacketLength member is already valid.

dwProvSpec2

Specifies provider-specific data. Applications should ignore this member unless they have detailed information about the format of the data required by the provider.

wcProvChar

Specifies provider-specific data. Applications should ignore this member unless they have detailed information about the format of the data required by the provider.

Remarks

The contents of the dwProvSpec1, dwProvSpec2, and wcProvChar members depend on the provider subtype (specified by the dwProvSubType member).

If the provider subtype is PST_MODEM, these members are used as follows:

See Also

GetCommProperties