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Error 200524 Different number of channels in task and data


Anyone out there with some information would be greatly appreciated. I  have attached my VI. Essentially I am trying to build a simple PID VI to controll the temperature of a piece of equipment in a system I am building. I have heating wire powered by 120 V source. The circuit is controlled by a simple relay, which is controlled by a digital line on my NI USB 6343 board. I have seen numerous examples throughout the forums and the shipped examples, but I cannot seem to figure out how the PID VIs work. I understand the basics of a PID controller, but cannot make the connections of how to actually get it to work in LV.

I figured that this VI I wrote is pretty simple and should work, but I keep getting this error.


Error -200524 occurred at


Possible reason(s):

Write cannot be performed, because the number of channels in the data does not match the number of channels in the task.

When writing, supply data for all channels in the task. Alternatively, modify the task to contain the same number of channels as the data written.

Number of Channels in Task: 1
Number of Channels in Data: 1000

Task Name: _unnamedTask<1>"


Any advice, direction, sample VIs that are not overly complicated, etc would be greatly appreciated.

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Revised my VI to an earlier iteration that makes more sense to me.

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Hi andyabs,


I'm not getting the same error you are when running this VI.  How are you setting up your channels and tasks in the DAQ Assistants?  It seems like this may be the source of your error.


You should also take a look at Section 4 of the attached White Paper.  Using DAQmx functions rather than the DAQ Assistant will give you a bit more functionality with your program.  Let me know if you have any questions about this example.


Control Applications with Data Acquisition Hardware:



Applications Engineer

National Instruments

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