COMMPROP  MAFSH_ 

The COMMPROP structure is used by the GetCommProperties16DV39W 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:

Value

Meaning

BAUD_075

75 bps

BAUD_110

110 bps

BAUD_134_5

134.5 bps

BAUD_150

150 bps

BAUD_300

300 bps

BAUD_600

600 bps

BAUD_1200

1200 bps

BAUD_1800

1800 bps

BAUD_2400

2400 bps

BAUD_4800

4800 bps

BAUD_7200

7200 bps

BAUD_9600

9600 bps

BAUD_14400

14400 bps

BAUD_19200

19200 bps

BAUD_38400

38400 bps

BAUD_56K

56K bps

BAUD_57600

57600 bps

BAUD_115200

115200 bps

BAUD_128K

128K bps

BAUD_USER

Programmable baud rates available

 

dwProvSubType

Specifies the specific communications provider type:

Value

Meaning

PST_FAX

FAX device

PST_LAT

LAT protocol

PST_MODEM

Modem device

PST_NETWORK_BRIDGE

Unspecified network bridge

PST_PARALLELPORT

Parallel port

PST_RS232

RS-232 serial port

PST_RS422

RS-422 port

PST_RS423

RS-423 port

PST_RS449

RS-449 port

PST_SCANNER

Scanner device

PST_TCPIP_TELNET

TCP/IP Telnet  protocol

PST_UNSPECIFIED

Unspecified

PST_X25

X.25 standards

 

dwProvCapabilities

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

Value

Meaning

PCF_16BITMODE

Special 16-bit mode supported

PCF_DTRDSR

DTR (data-terminal-ready)/DSR (data-set-ready) supported

PCF_INTTIMEOUTS

Interval time-outs supported

PCF_PARITY_CHECK

Parity checking supported

PCF_RLSD

RLSD (receive-line-signal-detect) supported

PCF_RTSCTS

RTS (request-to-send)/CTS (clear-to-send) supported

PCF_SETXCHAR

Settable XON/XOFF supported

PCF_SPECIALCHARS

Special character support provided

PCF_TOTALTIMEOUTS

Total (elapsed) time-outs supported

PCF_XONXOFF

XON/XOFF flow control supported

 

dwSettableParams

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

Value

Meaning

SP_BAUD

Baud rate

SP_DATABITS

Data bits

SP_HANDSHAKING

Handshaking (flow control)

SP_PARITY

Parity

SP_PARITY_CHECK

Parity checking

SP_RLSD

RLSD (receive-line-signal-detect)

SP_STOPBITS

Stop bits

 

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:

Value

Meaning

DATABITS_5

5 data bits

DATABITS_6

6 data bits

DATABITS_7

7 data bits

DATABITS_8

8 data bits

DATABITS_16

16 data bits

DATABITS_16X

Special wide path through serial hardware lines

 

wSettableStopParity

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

Value

Meaning

STOPBITS_10

1 stop bit

STOPBITS_15

1.5 stop bits

STOPBITS_20

2 stop bits

PARITY_NONE

No parity

PARITY_ODD

Odd parity

PARITY_EVEN

Even parity

PARITY_MARK

Mark parity

PARITY_SPACE

Space parity

 

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:

Value

Meaning

dwProvSpec1

Not used.

dwProvSpec2

Not used.

wcProvChar

Contains a MODEMDEVCAPS0XBD43 structure.

 

See Also

GetCommProperties