Best timing method for Digital Output for NI PXI 6527?

[itoma054]

Hello,

I am trying to improve the timing reliability of changing the digital output values for a NI PXI 6527. I have attached an image of a snippet of code demonstrating my current method of:

-writing the output values

-waiting until time has expired

-writing new output values, and so on.

Unfortunately, I find this method does not have very reliable timing, and my switches do not always turn on and off when they should.

I was thinking that a better approach was to have some kind of "script" that updated the output values at a specified rate. I thought the example VI "Digital - Continuous Output" was a good starting point, however, I continue to get the following error:

Possible reason(s):

Requested value is not a supported value for this property. The property value may be invalid because it conflicts with another property.

Property: SampTimingType
Requested Value: Sample Clock
Possible Values: On Demand, Change Detection

Task Name: _unnamedTask<2D>

I am using the OnboardClock as my Sample Clock Source. In the VI description, it says it is supported by PXI 6527, but I can't seem to make it work.

Any help on:

1. Improving the timing reliability of changing digital output values or;

2. Resolving the above error when executing the "Digital - Continuous Output" VI with a NI PXI 6527 and using the OnboardClock.

Would be greatly appreciated!

Thanks,

Ian

[this_one_time_at_vancamp]

itoma054,

Does the original code that you were using use the same clock?

I found this forum post where someone has a similar issue: https://forums.ni.com/t5/Multifunction-DAQ/Error-200077-occurred-at-DAQ-Assistant/td-p/845960 

Just to see if the clock is the issue, try changing the Write in the example to 1 sample, making it On Demand.

Also, I assume the Channel Line(s) input in the example is properly set to a channel on that board?

MVC