Academic Hardware Products (myDAQ, myRIO)

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Simultaneously control QUBE servo motor and read analog input using myRIO

I am currently trying to use the myRIO to control the Quanser QUBE servo motor (through the MXP port) based on an analog input signal. Individually, I can control the QUBE motor using Quanser add-on toolkit and read an analog voltage signal using standard myRIO functions. However, when I simultaneously control the motor and read an analog input (using the other available AI pin), I receiving error regarding the FPGA. If the QUBE HiL Initialize function was called first, an error was received for the AI Open VI:


If the AI Open was called first, the QUBE gave the following error: 


The VI snippet:


The attached VI is LabVIEW 2017 and require Control Design and Simulation module and Quanser Rapid Control Prototyping toolkit. However, the key problems have been outlined above. Thank you in advance for your support. 

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Message 1 of 4

Hi there,


This is the explanation of the first error code:


Error -61200 occurred at an unidentified location

Possible reason(s):

LabVIEW FPGA: The operation could not be performed because the FPGA is busy operating in FPGA Interface C API mode. Stop all activities on the FPGA before requesting this operation.


I looks like simultaneously reading the input while controlling the motor is not possible.


The explanation of the second error is this:


Error 400328 occurred at an unidentified location

This error code is undefined. Undefined errors might occur for a number of reasons. For example, no one has provided a description for the code, or you might have wired a number that is not an error code to the error code input.

Additionally, undefined error codes might occur because the error relates to a third-party object, such as the operating system or ActiveX. For these third-party errors, you might be able to obtain a description of the error by searching the Web for the error code (400328) or for its hexadecimal representation (0x00061BC8).


So not much to learn from it. 


Maybe try to change your application so that you do not read while moving the motor?


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Message 2 of 4

Hi Notanae,

Thank you for your reply. I have looked up these error codes and found the same thing. I am trying to control the motor operation based on a signal from a sensor, so the myRIO have to simultaneously control the motor and read an analog input 😞 I can't find a way around this.


I've tried to run the motor without using the Quanser toolkit (i.e. measure the signal on the output pins when using the Quanser toolkit and then replicate them using standard myRIO function). The motor did run but it was making a bad noise even at low speed.

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Message 3 of 4

How about trying to include your measurement in the initially running FPGA program?

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Message 4 of 4