C.kt

Hello Expert,

I would like to try and implement simple PID blockfor myself. i always have this idea and beleive this time is best for me to startup. I am awared that SIEMENS already provided PID block "CONT_C" ..., etc too . When i search, i found below and can anybody share something to me if you have it especially "dt calculation". i prefer SCL and as always, appreciated your help.

// Pseudo code (source Wikipedia)

previous_error = 0

integral = 0 ;

Begin

error = setpoint – PV [actual_position] ;

integral = integral + error * dt ;

derivative = (error - previous_error)/dt ;

output = Kp * error + Ki * integral + Kd * derivative ;

previous_error = error ;

Really happy to see somebody think differently in the forum and seeking for challenges.I can say it is good.I have developed my controller and tuner blocks based on experience and data from published materials (Books and published papers in control and signal processing journals).I have tested them in real cases as a transient solutions but there are several modified cases ,I added to reach this point.You can work on and share the result for our judgement.We know the pitfalls and test it for that challenging criteria derived from experience.

At least, that try , make you more knowledgeable in regulations.