PID controller use
For precise and highly dynamic control not allowing a continuous error variable.
8.7.3.
Setpoint source (input for process setpoint)
Customer settings M0041
Process controller M0742
Setpoint source M0743
Default value:
I/O interface
Setting values:
I/O interface
The process setpoint is defined via an analogue input (AIN 1 or AIN 2) of the I/O
interface.
Fieldbus interface
The process setpoint is defined via fieldbus.
Internal setpoint
The process setpoint is generated internally via actuator controls. Parameters
Internal
setpoint 1 M0749
/
Internal setpoint 2 M0750
Information
To use internal setpoint 2, a digital input must be configured accordingly.
8.7.4.
Behaviour on loss of process setpoint
Customer settings M0041
Process controller M0742
Beh. setpoint failure M0747
Default value:
Internal setpoint 1
Setting values:
Internal setpoint 1
In case of process setpoint signal loss, actuator controls switch to the internal setpoint
1. Parameter
Internal setpoint 1 M0749
Internal setpoint 2
In case of process setpoint signal loss, actuator controls switch to the internal setpoint
2. Parameter
Internal setpoint 2 M0750
Failure behaviour
In case of process setpoint signal loss, failure behaviour procedure is activated.
Parameter
Failure behaviour M0378
Last setpoint
In case of process setpoint signal loss, the last available process setpoint will still
be used as setpoint.
8.7.5.
Inverse operation
As standard, the valve is opened by the modulating actuator as soon as the actual
process value falls below the process setpoint. Depending on the process, it may,
however, be necessary that the valve closes as soon as the actual process value
falls below the process setpoint. In this case, the respective parameters are used to
set the process controller to inverse operation.
Customer settings M0041
Process controller M0742
Inverse operation M0748
Default value:
Function not active
Setting values:
Function not active
Inverse operation is deactivated.
Function active
Inverse operation is activated.
8.7.6.
Internal process setpoint
An internal process setpoint may be set with this parameter. The internal process
setpoint is used if:
●
Parameter
Setpoint source M0743
is set to
Internal setpoint
or
●
Parameter
Beh. setpoint failure M0747
is set to
Internal setpoint 1
or
Internal
setpoint 2
.
70
Actuator controls
Application functions
ACV 01.2/ACVExC 01.2 Profibus DP