Occasional Error-50103 Appearance

[FaisalF]

Dear All

I am building a code that I want it to do the following:

1- output a triangular waveform with a specific frequency and amplitude.

2- then after the triangular waveform automatically output a sine wave with onother prespecified frequency and amplitude.

3- these two consecutive waveforms are supposed to be going out from the same cahnnel (AO0).

4- during the above happens and at the same time I am receiving two signals from two sensors >> calculating the difference between the two received signals >>> then outputting the difference from another channel (AO1).

My problem is the code some times is working fine and sometimes giving me the following error:

Error-50103.....

Possible reason(s):

NI Platform Services: The specified resource is reserved. The operation could not be completed as specified.

Task Name: _unnamedTask<19DB>

Please advice

p.s you can find the VI that I am talking about in the attachments

Many thanks in advance 

[P@Anand]

The error you have shown occurs when you try to access the same resource at 2 different places. Since I don't have DAQmx installed I am not able to look into the code completely. 

Since you are trying to access the AO0 and AO1 in 2 different places you are getting the error. I believe both the output share the same DAC. What is the DAQ card you are using?

[FaisalF]

I am using PCIe-6321 and SCB-68A.

I dont think that this is the problem because in previos (earlier) versions of my code every thing was running fine and smooth. I was outputting a sine wave from AO0 and inputting the sensors signal and making the calculations and reoutputting the result from AO1.

but now I am trying to add to the code and it works fine but occasionally it give me the 50103 error.

[BigShotEngineer]

I too have experienced this occassional 50103 error.  It is quite infrequent and it's difficult to reproduce for troubleshooting purposes, so I don't know if this was the fix or not, but what I did was place a time delay between the two consecutive daqmx calls (to different channels of course), using error wires to determine execution flow, and I have not seen this error show up since.    Perhaps someone else has fiddled around with it more and actually found the root cause? I haven' tbeen able to sofar. 

[Dennis_Knutson]

You've already been told the root cause. The error is a common one. You simply cannot have multiple tasks running that use the same resource. As mentioned, there is a single convert clock. If you find out difficult to combine multiple channels into a single task, the first task must be stopped and cleared before you start a second task. Using error wires is the correct way to enforce execution order. Not having them was bad design.