Temp control

Dear experts 

Function block pid_compact  is used to control the temperature through PWM, the controller is doing well to achieve the targeted temperature but when the power switched off and on again on the controller, there's no output from the controller for along time until the temp actual value decreases about 40 celuis below temp set point , then the controller back again to respond to changes 

1214C DC/DC/DC controller 

Tia portal V13 

Thanks in advance

Hello,

please try another start value for "IntegralResetMode" than the default value 1 = clear (e.g. 0 = smooth or 3 = overwrite initial output):
https://support.industry.siemens.com/cs/ww/en/view/108210036/82409255819

I have tried that but there's no changes, the best result was at value 1

I think the error may be in pid parameters which resulting from auto tune

 Any help? 

hossamhegab

Dear experts 

Function block pid_compact  is used to control the temperature through PWM, the controller is doing well to achieve the targeted temperature but when the power switched off and on again on the controller, there's no output from the controller for along time until the temp actual value decreases about 40 celuis below temp set point , then the controller back again to respond to changes 

1214C DC/DC/DC controller 

Tia portal V13 

Thanks in advance

hossamhegab

Dear experts 

Function block pid_compact  is used to control the temperature through PWM, the controller is doing well to achieve the targeted temperature but when the power switched off and on again on the controller, there's no output from the controller for along time until the temp actual value decreases about 40 celuis below temp set point , then the controller back again to respond to changes 

1214C DC/DC/DC controller 

Tia portal V13 

Thanks in advance

 WHat you need to do is PID reinitialisation. I usually do that every signle time once PID is activated.

So lets say on positive edge of the bit tempPIDactive.

What does initialisation do?

1.It sets PID output on some value which you chose,( you are doing this by moving your desired value inside INTEGRAL part of your PID.)

2. You set reference and measuring value the same and thats in most case the measuring value.