COMM-DRV/VxD Technical Specifications

COMM-DRV/VxD was designed with interoperability in mind. It uses the Windows standard DLL calling conventions. As such, COMM-DRV/VxD may be integrated with any Windows tool, application, or language that can call the Windows API (WIN16 or WIN32). COMM-DRV/VxD may be used with Visual C/C++, Borland C/C++, Watcom C/C++, Visual Basic, Access, Excel, Paradox, and a myriad of other tools and applications.

COMM-DRV/VxD is extremely easy to use. The API is simple, concise, and intuitive. Ample examples are provided. COMM-DRV/VxD may be integrated with all other WCSC communication products.

• Provides support for RS485/RS422 devices. It can automatically drop the RTS signal when all data has been transmitted for optimum control of the RS485 buses or other devices requiring said protocol.
• Provides built in support for the nine bit protocol. With one call the first byte is sent with 9 bits while the others are transmitted normally.
• Supports WIN32, WIN16, CONSOLE, and MS-DOS applications running concurrently.
• Supports any number of serial ports active concurrently with receive and transmit buffers of any size.
• Supports baud rates in excess of 400K.
• Provides automatic hardware flow control(RTS/CTS, DTR/DSR), as well as software flow control(XON/XOFF).
• Provides seamless integration with COMM-DRV/Lib and COMM-DRV/Dos.
• Supports the built in PC COM ports and ALL non-intelligent multiport cards based on the 8250, 16450, 16550, 16650, and 16750 family of UARTs.
• Peek ahead virtually any number of bytes.
• Interrupts, buffering, and flow control handled in 32 bit mode of the CPU in Ring 0.
• Autodetects 16550 and uses it in high speed mode.
• Allows sharing IRQs on supporting hardware.

COMM-DRV/VxD Application Programming Interface (API)

• WCSCVxDBreakOff Resets the port from the break state.
• WCSCVxDBreakOn Puts the port in the break state.
• WCSCVxDBytesInRcvBuf Returns number of bytes in receive buffer.
• WCSCVxDBytesInXmtBuf Returns number of bytes in transmit buffer.
• WCSCVxDCleanup Closes an opened port.
• WCSCVxDDtrOff Turn DTR off.
• WCSCVxDDtrOn Turn DTR on.
• WCSCVxDFlush Purges communication buffers.
• WCSCVxDGetMetrics Return port statistics on specific items.
• WCSCVxDGetPacket Get a packet of data.
• WCSCVxDGetPort Get port metrics.
• WCSCVxDGetRegister Read an 8250/16450/16550 register value.
• WCSCVxDInit Map dynamically to the VxD.
• WCSCVxDInitializePort Open a port.
• WCSCVxDIsAllDataOut Returns true if transmit buffer is empty as well as the UART is empty.
• WCSCVxDOpenPort Opens the serial port(preferred).
• WCSCVxDPutPacket Output a packet of data.
• WCSCVxDPutRegister Write to an 8250/16450/16550 register.
• WCSCVxDRtsOff Turn RTS off.
• WCSCVxDRtsOn Turn RTS on.
• WCSCVxDSetBaudDiv Set new baud rate divisor(for non standard baud rates).
• WCSCVxDSetPortCharacteristics Set new port characteristics(baud rates etc.).
• WCSCVxDSetup Extended port open.
• WCSCVxDSizeOfRcvBuf Get size of receive buffer.
• WCSCVxdSizeOfXmtBuf Get size of transmit buffer.
• WCSCVxDSpaceInRcvBuf Get available space in receive buffer.
• WCSCVxdSpaceInXmtBuf Get available space in transmit buffer.
• WCSCVxDViewPacket Non-destructively reads a packet of data.