COMM-DRV/NT – High speed serial communication kernel driver


COMM-DRV/NT is the state of the art serial communications (RS232, RS485, RS422) Kernel Device Driver for Windows 2003, Windows XP, Windows 2000, and Windows NT. It provides crisp, fast, and reliable performance from the aging 8250, and 16450 UARTs as well as lightning fast performance from the 16550/16650/16750 family of UARTs.

SKU: COMMDRVNT Categories: ,


COMM-DRV/NT - High speed serial communication kernel driver


COMM-DRV/NT is the state of the art serial communications (RS232, RS485, RS422) Kernel Device Driver for Windows 2003, Windows XP, Windows 2000, and Windows NT. It provides crisp, fast, and reliable performance from the aging 8250, and 16450 UARTs as well as lightning fast performance from the 16550/16650/16750 family of UARTs.  

If your application requires ultra fast serial communications, fast response on the RTS signal for multidrop applications (RS485), and/or nine-bit protocol support, then COMM-DRV/NT is the tool of choice for these applications.

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Who is a candidate for COMM-DRV/NT? 

COMM-DRV/NT is perfect for applications where any of the following applies:

  • Need for high speed and/or reliable serial communication on one or more ports concurrently.

  • Need for multidrop protocol support (RS485).

  • Need for nine-bit protocol support.

  • Support for built in serial ports on motherboard(COM1, COM2, etc.).

  • Support for non-intelligent PCI & ISA multiport cards w/16×50 UARTs.

  • Need for support for the larger FIFOs of the 16650 family of UARTs.

  • Need for crisp support of hardware flow control built directly into UART.

  • Need for time stamping bytes with microsecond resolution.

  • Need callbacks on events including state of modem signals, line errors, break detection, and other events.

  • Need to have your 16 bit MS-DOS application run under Windows 2003, Windows XP,  Windows 2000, or Windows NT.

COMM-DRV/NT uses the Win32 standard DLL calling conventions. As such, it may be integrated with any Windows tool, application, or language that can call DLLs. COMM-DRV/NT 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/NT supports the multidrop protocol (RS485)directly from within its interrupt handlers. In this mode it drops the RTS immediately after the last byte leaves the UART. It is the fastest response currently available under Windows 2003, Windows XP, Windows 2000, or Windows NT.COMM-DRV/NT supports the nine-bit protocol. It transmits the first byte with the ninth bit set. It transmit all remaining bytes in the packet with the ninth bit cleared. It can read and write bytes using the nine-bit protocol  with the standard 16×50 family of UARTs. High Speed Serial Communication Kernel Driver DLL (Multidrop & Nine Bit Protocol, TimeStamps)

COMM-DRV/NT does not use any of the Windows 2003, Windows XP, Windows 2000 or Windows NT serial communication services or device drivers. It interfaces directly to the serial port. As such, there is no unnecessary layering of services that are time consuming. 

COMM-DRV/NT supports the time stamping of each byte that enters the UART. It provides microsecond resolution. It buffers the time stamp along side its byte data.

COMM-DRV/NT was designed with interoperability in mind. Its API is completely downwardly compatible to  our COMM-DRV/VxD product. In fact, the new DLL provided with COMM-DRV/NT will work under Windows 2003, Windows XP, Windows 2000, & Windows NT as well as under Windows Me, Windows 98 and Windows 95. Under Windows 2003, Windows XP, Windows 2000, or Windows NT the kernel driver shipped with COMM-DRV/NT is installed. Under Windows Me, Windows 98, or Windows 95 the VxD that ships with COMM-DRV/VxD would be installed. The software engineer/programmer need not worry about Windows platform since the interface is abstracted by the above mentioned DLL.

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

Technical Specifications:

  • 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 the ninth bit set  while the other bytes are sent with the ninth bit cleared.

  • 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, 16750, 16850 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.

  • Autodetects 16650 and can use built-in hardware flow control and larger FIFOs.

  • Allows sharing IRQs on supporting hardware.

  • Ability to provide time stamps on all inputted data.

  • Ability to save line status and modem status information with each byte that is buffered.

  • Provides for user function callback on specified events.

  • Provides for blocking calling thread till specified event occurs.

 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.
WCSCVxDCallbackOnEvent() Callbacks a user function on the particular event.
WCSCVxDCleanup() Closes an opened port.
WCSCVxDDeleteEvent() Deletes an outstanding event.
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.
WCSCVxDWaitForEvent() Puts calling thread to sleep until event occurs.