Watlow CPC400 - Manual (Page 95)

Doc. 0600-2900-2000 Watlow Anafaze 81
4
Tuning and Control
This chapter describes the different methods of control
available with the CPC400. This chapter covers control al-
gorithms, control methods, PID control, starting PID val-
ues and tuning instructions to help appropriately set
control parameters in the CPC400 system.
For more information about PID control, consult the Wat-
low Anafaze Practical Guide to PID.
Control Algorithms
This section explains the algorithms available for control-
ling a loop.
The control algorithm dictates how the controller responds
to an input signal. Do not confuse control algorithms with
control output signals (for example, analog or pulsed dc
voltage). There are several control algorithms available:
• On/off
• Proportional (P)
• Proportional and integral (PI)
• Proportional with derivative (PD)
• Proportional with integral and derivative (PID)
P, PI or PID control is necessary when process variable cy-
cling is unacceptable or if the load or set point varies.
NOTE! For any of these control algorithms to function,
the loop must be in automatic mode.