Napo_2012

Problem with PID controller in FX3U

6 posts in this topic

Hi,

I have problem and hope if there is anyone who has same kind of problem, could tip me to the right direction. I have scrolled online for solution, but found nothing to solve this. Im makin heating/cooling control for radiator system. Basically temperature measurement that controls 0-10v valve. Pretty straight forward operation. Im having trouble getting PID control block to work on cpu. When in simulation mode PID works perfectly, but  when i download program to FX3u CPU, PID output stays at zero. No matter what values i give to PID, manipulated output is frozen. I attach some images that will show how its running. Tried few different PID's and results are the same. So im thinking there is some trick to the cpu to start executing this block. If you have some tips, i would be gratefull :).

https://ibb.co/rpqFtLN

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Maybe you should attach the program, so we can test it.

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Hmm, judging by RD3A command, you are using, I'm presuming it is not original FX3U, but china clone. Am I right?

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You got that right. Got this one almost by accident and tought it would suit well for this small project.Haven't worked that much with mitsubishi projects, but could this be that the clone model is not able use these library imported pid's somehow. Was it difficult to make one of the basic PID blocks to work that can be found in basic block listing? I think that will be my next try for solution in this case :)

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As I'm been informed clones do not have complete compatibility and do not work good with GX Works2 nor with GX IEC Developer, but only with GX Developer. Additionally  SimplePID library is originally made for GX IEC Developer. Also I, personally,  would never use clone for heating radiators due to potential safety issues.

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