Vidmas30 Posted February 9, 2017 Report Share Posted February 9, 2017 Good morning, We have a v570 PLC running on site for about 6years, controlling el. actuator (steam-water) by set temperature. Something happened and it began to work very bad - tmperature is too low or too high. In case we don't have posibility t check this matter on site, we gave a password to PID parameter window and suggested to check if it's OK with P,I,D variables. So the matter is: 1. After they tried PID autotune it done about 10 cycles and calculated souch parameters P: -0.3%, I: -0.2%, D: 2s. The control was not good. After repeated autotuning it calculated the same parameters. Question: why there are negative values? We suggested customer to tune PID manually. Then.. 2. After some manual tuning it was pretty OK, but then some colegue pushed an autotune button again, they tried to stop it and now seems like PID block is hanged up - after reseting PLC, PID status shows autotune is running, but CV value is not changing. How to reset PID block? Thank you! Quote Link to comment Share on other sites More sharing options...
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