Be very careful about installing non-standard serial cards in a PC
running NT. The NTSERIAL driver will try to control these non
standard cards (but won't be able to) and won't let the manufacturer's
driver control it unless you follow the card manufacturer's
instructions to the letter. Typically this involves installing the
manufacturer's software FIRST, setting the configuration, setting any
dipswitches or jumpers on the card, and THEN LAST, powering down,
installing the card, and powering back up. BUT PLEASE FOLLOW THE
MFG's INSTRUCTIONS, not mine if they differ.
Blackbox makes an RS422/485 card and I believe so does NI.
Douglas De Clue
LabVIEW programmer
ddeclue@bellsouth.net
Sanjay wrote in message news:<50650000000500000063
8A0000-1023576873000@exchange.ni.com>...
> 1) The standard/built-in serial ports on your computer are almost
> certainly not RS-422 compatible (they're actually almost certainly
> RS-232). NI (amongst other serial vendors) sells RS-485 serial
> interfaces that are fully RS-422 compatible.
> 2) From a software standpoint you can use the VISA-Serial VIs
> (recommended) or the I/O compatibility VIs to control either RS-232,
> RS-422 or RS-485.
