How to avoid unexpected pulse on a port when I operate on other port on 6025E

[wusheng]

I need to do the digital IO on two or three ports simultaneously in a same VI.
I configured the PA, PB, PC using the 'DIO Port Config.vi' first, and then to
exexute the IO operation, but when I trying to change some value on a line of
a port, I always get an unexpected pulse on other ports. What is the reason for
this?

And instead of using the 'DIO port Config.vi', I also tried the 'DIO Group Config.vi'
the phenomenon is the same.

[Ben]

Please post an example showing what you are trying.

It sounds like you are using a high level function that resets the port before writting the new value.

Ben

[Doug_Norman]

After calling DIO Port Config.vi try using DIO Port Read.vi and DIO Port Write.vi. These advanced VIs should not reset your port.

Regards,

Doug

[Filipe A.]

Hello;

You didn't mention if you are doing all reads or all writes on the ports, but, you need to initialize all the ports before reading from or writting to them, otherwise the patterns on previosly configure ports will be lost, and you might see the behavior you described.

Hope this helps.
Filipe A.
Applications Engineer
National Instruments