Set input value from Custom Device

[DaHelmut]

Hi,

I am actually creating a custom device (asynchronous) that is controlling a climatic system. It consists in adapting a functionnal LabVIEW code to create the custom device. Unfortunately the LabVIEW code uses a lot of FGVs that act as inputs and outputs at the same time (it means that the system can change the value of an input).

So, I would like to know if there is an easy way to set the value of an input from the custom device engine code. I tried the following solutions without success :

• Write into the FIFO of the input channel.
• Use "Set Channel Value" of the NI VeriStand API -> I get the error -307970.

So, is there something I can do to facilitate my custom device creation ? instead of "re-thinking" the whole code which is a real pain in the *** because of the complexity of it ?

Thanks in advance.

[thumble]

Hi,

I think you can do it from an Inline custom device, but you need to set the direction of your channel (flags) as readable and writable so you can do the both operations.

Best regards

[DaHelmut]

Hi,

Yep but I can't use the inline template since my code isn't really deterministic and too slow. Using an inline one would require too much time. I can't afford it. Moreover there is more than one loop.

Regards,

[thumble · Accepted solution]

Re,

We solved that by using the inllne part for only channel updating and defering the real treatments to asynchronous threads with data exchanges through FIFOs.

++

[DaHelmut · Accepted solution]

This could be a solution. Didn't think about it....Thanks a LOT !

[Jiri_K]

Actually we use such apporach in our custom devices.There is a library, that helps with managing of  the asynchronous process.

You can look at the source f.e. of following custom device including the library: https://github.com/NIVeriStandAdd-Ons/CANopen-Master-Custom-Device

~Jiri