Posted 9 May 2018 Dear All i am trying to control pneumatic valve with level of tank. User set the desired level and pneumatic valve control the level in tank.. Tank level is 4-20ma signal. With empty tank it show value if 3 and if level is full it shows reading of 151. I am using FX3U PLC for this purpose. I tried to control it using PID function. I set Kp to 300 and Ti to 2sec derivative term is zero. With these set parameters system act just like a switch it turn on valve full open when PV(Level measured value) is less then SV(level set value) and turn the valve completely off when PV is greater then SV. Kindly help me to tune the system properly Thanks Bilal Khan Share this post Link to post Share on other sites