increase buffer size

[exploradora01]

Hello all,

I'm trying to take 6 AI voltage measurements, convert, and then send to 6 current AO, so I'll have continuous samples for every channel. I got the error 200609, which wants me to increase the buffer size where selected buffer size:1 and Minimum Required Buffer Size:2. 

I tried correcting this error by adding the configure output buffer and adding the constant 2, where then it gives me error 200524, saying:

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: 2

I've been stuck for a couple days now trying what's been recommended in the forums...what do I need to do in order to get this program to work?  Attached is the program. I just started working with Labview a few weeks ago, so I'm a beginner.

Any help is greatly appreciated!

[Sam_Sharp]

Is it definitely your AO task that's producing the error?

You need to be really careful about the rates at which your cDAQ is producing data (based on the timing / sample rate) and how much data you are reading (while loop rate and samples read per channel).

When you are writing the output, are you actually trying to write a waveform of points (multiple samples for each channel) or just update the output (1 sample for each channel).

Be careful with your execution timing as well - your execution timing might be slowing down your loop such that you're not reading the points quickly enough.

Also - you should try to avoid using the dynamic data type wherever possible - it's usually much better to use the proper labview data types.

[exploradora01]

Hello Sam,

When I run the program, I see that the error 200609 is coming from the Daqmx Write vi (without the configure buffer output vi).  I'm trying to write this for my mentor so she wants it to update the output where we'll just have 1 sample per channel. 

I understand that timing is important, but I'm not sure how to make this program execute in the most efficient way. 

Is there an example in my code where I can use the proper labview types or even from another example?

Thank you for your response.

[Sam_Sharp · Accepted solution]

Try removing the sample clock VI on the output task and write NChan 1Sample inside your while loop to update the outputs.

[exploradora01]

That worked along with taking out the build array inside the for loop!

Thank you for your help!!