07-09-2022 01:49 PM
Dear all,
I am trying to do motion control of a hydraulic cylinder using PID vi. The hardware I used includes NI 9220 for LVDT voltage input, NI 9269 for voltage output, and NI 9213 for temperature input.
The problem is that when I acqusite extra temperature data from NI 9213, the elapsed time of PID vi becomes extremely slow, leading to failure of PID control due to the low loop frequency.
Does anyone encounter similar problem?
Attached please find the programme used.
Best Regards,
Roy
Solved! Go to Solution.
07-10-2022 03:59 AM
07-10-2022 07:47 AM
Hi Roy,
now I had a chance to look into your VI…
@Roy19 wrote:
The problem is that when I acqusite extra temperature data from NI 9213, the elapsed time of PID vi becomes extremely slow, leading to failure of PID control due to the low loop frequency.
That's not a problem of the PID functions, but of your data acquisition!
Recommendations:
07-18-2022 06:02 AM
Dear GerdW,
Thanks for all your comments. They really help a lot!
Regarding the PID gains, because I modified the programme from the PID example, so the PID gains would always recover to its default values of [10.0, 0.01, 0.001]. This also happens for the PID profile. Save the file doesnot help at all. Is there any method to solve this so that I do not need to reinput all the gains and profiles again.
Best Regards,
Roy
07-18-2022 06:21 AM
Hi Roy,
@Roy19 wrote:
Is there any method to solve this so that I do not need to reinput all the gains and profiles again.
You need to set new default values, either by right-clicking the controls (->Data->set as default) or by using the edit menu -> set as default…