This structure is used by the GetCommProperties function to return specific communication support driver data.
At a Glance
| Header file: | Winbase.h |
| Windows CE versions: | 1.0 and later |
Syntax
typedef struct _COMMPROP {
WORD wPacketLength;
WORD wPacketVersion;
DWORD dwServiceMask;
DWORD dwReserved1;
DWORD dwMaxTxQueue;
DWORD dwMaxRxQueue;
DWORD dwMaxBaud;
DWORD dwProvSubType;
DWORD dwProvCapabilities;
DWORD dwSettableParams;
DWORD dwSettableBaud;
WORD wSettableData;
WORD wSettableStopParity;
WORD dwCurrentTxQueue;
DWORD dwCurrentRxQueue;
DWORD dwProvSpec1;
DWORD dwProvSpec2;
WCHAR wcProvChar[1];
} 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 acceptable baud rate, in bits per second (bps). It is one of the following values:
| Value | Description |
| 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. It is one of the following values:
| Value | Description |
| 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
Indicates the capabilities offered by the provider. It is one of the following values:
| Value | Description |
| PCF_16BITMODE | Special 16-bit mode is supported. |
| PCF_DTRDSR | DTR (Data Terminal Ready) and DSR (Data Set Ready) are supported. |
| PCF_INTTIMEOUTS | Interval time-outs are supported. |
| PCF_PARITY_CHECK | Parity checking is supported. |
| PCF_RLSD | RLSD (Receive Line Signal Detect) is supported. |
| PCF_RTSCTS | RTS (Request to Send) and CTS (Clear to Send) are supported. |
| PCF_SETXCHAR | XON and XOFF are supported. |
| PCF_SPECIALCHARS | Special character support is provided. |
| PCF_TOTALTIMEOUTS | Total, elapsed, time-outs are supported. |
| PCF_XONXOFF | XON and XOFF flow control are supported. |
dwSettableParams
Indicates the communication parameter that can be changed. It is one of the following values:
| Value | Description |
| SP_BAUD | Baud rate |
| SP_DATABITS | Data bits |
| SP_HANDSHAKING | Handshaking (flow control) |
| SP_PARITY | Parity |
| SP_PARITY_CHECK | Parity checking |
| SP_RLSD | Receive Line Signal Detect |
| SP_STOPBITS | Stop bits |
dwSettableBaud
Indicates the baud rates that can be used. For values, see the dwMaxBaud member.
wSettableData
Indicates the number of data bits that can be set. It is one of the following values:
| Value | Description |
| 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
Indicates the stop bit and parity settings that can be selected. It is one of the following values:
| Value | Description |
| PARITY_EVEN | Even parity |
| PARITY_MARK | Mark parity |
| PARITY_NONE | No parity |
| PARITY_ODD | Odd parity |
| PARITY_SPACE | Space parity |
| STOPBITS_10 | 1 stop bit |
| STOPBITS_15 | 1.5 stop bits |
| STOPBITS_20 | 2 stop bits |
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 specific data about the data format required by the provider is available.
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 specific data about the data format required by the provider is available.
wcProvChar
Specifies provider-specific data. Applications should ignore this member unless specific data about the data format required by the provider is available.
Remarks
The contents of the dwProvSpec1, dwProvSpec2, and wcProvChar members depend on the provider subtype; this is specified by the dwProvSubType member.
If the provider subtype is PST_MODEM, these members are used as follows:
| Value | Description |
| dwProvSpec1 | Not used |
| dwProvSpec2 | Not used |
| wcProvChar | Contains a MODEMDEVCAPS structure |
See Also