Watlow Controls 8LS, User Manual

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Tuning and Control
8LS User’s Guide 75
Tuning and Control
Introduction
This chapter explains PID control and supplies some starting PID values
and tuning instructions, so that you can use control parameters
appropriate for your system. If you would like more information on PID
control, consult the Watlow Anafaze
Practical Guide to PID .
The control mode dictates how the controller responds to an input
signal. The control mode is different from the type of control output
signal (like analog or pulsed DC voltage). There are several control
modes available: On/Off, Proportional (P), Proportional and Integral
(PI), Proportional with Derivative, and Proportional with Integral and
Derivative (PID). P, PI, or PID control are necessary when process
variable (PV) cycling is unacceptable or if the process or setpoint (SP) is
variable.
NOTE
For any of these control modes to function, the
loop must be in automatic mode.