©NationalInstruments Corporation 6-1 SerialHardware and Software for Windows
6
Using Your Serial Hardware
Thischapter describes how to set the hardware transceiver control mode for
yourRS-485 interfaces and lists some general programming requirements.

General Programming Requirements

The NI-Serial software is fully integrated into the standard Windows
communicationssoftware. NI serial ports are used like any other Wind ows
communications (COM) port. Windows has standard communication
functions for use within either Win16 or Win32 applications.
Whenyou develop your application, remember that you must use
the standard Microsoft Windowsserial communication functions. For
information about Microsoft Windowsserial communication functions,
referto theWin32 SoftwareDevelopment Kit andtotheWin32Overviews
and Win32 Reference online help.
Ifyou have LabVIEW or Measurement Studio and want to use it with your
serialhardware, refer to your LabVIEW or Measurement Studio
documentation for information about serial I/O functions.

Advanced Transceiver Control for the

PCI/PXI/PCMCIA/AT-485Boards

Note Transceivermodes apply only to the PCI/PXI/PCMCIA/AT-485boards.
The RS-485 boards support four modes of hardware transceiver control.
Youcan use hardware flow control to enable and disable your transmitters
and receivers so that they function on different bus topologies. Table 6-1
liststhe status o f the transmitters and receivers under each of the
transceiver control modes.