Self-Optimization - nvent raychem tcontrol-cont-03 Operating And Installation Manual

8.3

Self-optimization

Principle
Self-optimization (SO) is carried out according to the oscillation
method and establishes the optimum controller parameters for
PID or PI controllers.
Depending on the configured controller type, the following
controller parameters are defined:
Proportional band (Pb), derivative time (dt), reset time (rt), cycle
times (Cy), filter time constant (dF)
Depending on the range of the control deviation, the controller
selects between to methods a or b:
a) SO in start-up phase
x
w
T
S = Switching level
T = Start of self-optimization (SO)
Prerequisites
The following prerequisites must be fulfilled to be able to start
self- optimization:
• No active level inhibit via binary functions (binF)
• No active inhibit of Parameter level via Setup program (Display/
Operation/Service counter -> Operation -> Level inhibit)
• Ensure that the + keys are not pressed asynchronously.
Simultaneous actuation must be synchronous.
Furthermore, the following five points should be taken into
consideration, checked and, if necessary, adjusted, prior to
starting self-optimization:
• Is the suitable controller type configured?
• Check and/or adjust the control action of the controller
• Is it possible to sufficiently influence the process value in
manual mode?
• Prior to starting optimization on PID structure, ensure that the
reset time (rt) is not set to 0.
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b) SO at set point
x
S
w
t
T
t