Negative and positive output from pid

Hello ,

I want the pid on s71200 to output positive and negative signals how to do it?, The pid output signal will be used inside the program

 Try to change "Config.OutputLowerLimit" from 0 to a negative value like -100.0.For  a negative output , you need negative gain or negative error signal for a long period of time (in case of huge integration response).

I hope ithelps

hdhosseini

I tried to change lower limit to -100 but the output was zero also  it is hard to change pid gains to negative and positive on at once. It could be positive or negative on the same program 

 you are right , the min value for gain is 0 for PID compact, The only way to test is  the negative error .You need to provide PV value  higher than SP.I will share a video that illustrates my tests.

You defined pure p controller what if I need pi? 

 It is demo , you can decrease integration time from 100,000 seconds dramatically to a value that suits your process. The default value is 20 seconds.