How to read modify write a DO on the 6515

[VisualMath]

I have a 6515 and it does not look like board or dirver support the "don't modify option" (using DAQmx), so I need to find a way to read the DO state and then modify my output states before setting them.  I can't seem to find a way to do this using DAQmx.  How can I do this?  Will I have to use VISA to get this done, or will it not work either?

[Ed W]

Hi goslow,

Thanks for your post!

I’m not sure what you mean when you refer to the “don’t modify option” in DAQmx. 

However, you can read the value of your digital output before modifying it by simply jumpering the digital output line to a free digital input line.  That card (the NI-6515) has 32 inputs and 32 outputs, so you should probably have at least one extra digital input that you can use for this task.

I hope this helps!

Ed W.