Set 1 or more Digital outputs (6503)

[54577533trh]

Hi
i'm using a static dio card from national (6503) and labview.
i'd like to set 2 lines hi and lo each independet of the other.
my problem is: if i set one line high, all the other lines (from all ports) would be set to lo.
i'd like to change the stat of one line an the other ones should keep their states.. has anyone an idea how to realizie that?
thanks

[John N]

Hello,

The ports on those boards work a whole port at a time which is why you are not having luck setting one line without affecting the others. Here is some information I found for it by searching on the web site for <+dio +ports +reset>.
Characteristics of Devices that Use the 8255 Chip

The workaround would be to keep track of the output data in software, and change the data for a single bit in a software copy of the port. Then update the whole port.

Just for your information, on the E Series multifunction boards and on the NI 653x timed digital I/O boards, you can use lines individually.

I hope this helps to understand the
situation and get you started on something that will work for you.

Regards,

John N
Applications Engineer
National Instruments