ABB ControlMaster Series Manual page 14

ControlMaster CM30
Universal process controller,
Advanced control functionality
The CM30 features many advanced control functions providing
the power to bring even the most complex process under
control.
Autotune
Once initial configuration is complete, a powerful autotune
facility enables automatic calculation of the PID values
required, enabling rapid commissioning of the CM30.
Gain scheduling
The CM30's gain scheduling functionality is used for efficient
control of non-linear processes. Up to 3 different sets of PID
parameters are selected automatically from a reference signal
ensuring optimum control response, regardless of the process
status.
Reference
Signal
1.35
1.71
Time
Fig. 7: Gain scheduling example
6 DS/CM30–EN Rev. L | ControlMaster CM30 | Universal process controller,
P I D Gsref
3.5 2.71
67
0.0
4.8 15
33
2.62
4
/ DIN
1
4
Predictive control (dead-time compensation)
Control of processes with long dead-times, such as pH dosing
in a pipeline, is addressed easily using pPI control. Configured
via only 3 parameters (gain, integral time and dead-time), pPI
control can also be combined with gain scheduling for
optimum control efficiency.
Fig. 8: Predictive control example
Adaptive control
Adaptive control enables the CM30 to adjust its control
response automatically to suit changing process dynamics.
Limit 2
This makes the CM30 particularly useful for processes with
varying or uncontrolled types of load, by providing continuous
Limit 1
tuning to maximize control efficiency. Fig. 9 shows a product
used in a manufacturing process that is stored in an outside
tank. The use of adaptive control within the manufacturing
process compensates automatically for the change in product
temperature caused by seasonal variation.
Fig. 9: Adaptive control example
1 / DIN
4
PV
O/P
Dosing Pump
Deadtime
pH