pid output

[Gixxerash]

Hello,

i'm having problems with my pid in the sense that it only outputs 2 values(min and max).i've tried different gains and still, it will not operate properly.can anyone help me please? the process i'm tring to control is a oven, and i am using NI 6024E and SCC-2345.(i also tried without the dt s, by using a simple wait in the while loop, but it doesn't influence the it)

[nathand · Accepted solution]

Your output range is tiny (0 to 0.02).  Meanwhile your input appears to be on a much larger range.  Since your P gain is 20, any error (difference between setpoint and process variable) greater than 0.001 is going to be enough to drive the output either full on or full off (20 * 0.001 = 0.02).  You either need a larger output range (and then rescale before sending the output to the DAQ device) or much, much smaller gains (which could result in the loss of some mathematical precision).

[Gixxerash]

thank you, it seems to do the trick. thank you