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windell747
21-03-2009, 00:27
I have a really simple question. The values for the output of the PID within my loop is changing too fast for me to really tell, but if the setpoint is lower in value than the process variable value, is the output of the PID positive or negative?

Thanks!

Green2
21-03-2009, 00:59
PID should calculate set point minus process variable as the error...so if set point is low, the PID output is negative, provided the gains are positive.