Download FM 355 closed-loop control module

How Does the FM 355 Control?
3.4 Controller
Functions and parameters of the controller output
The following table lists the functions of the controller output and the setting possibilities.
Table 3-2
Functions of the controller output and setting possibilities
Functions of the controller output
Adjustable parameters
Switching of external manipulated value
The changeover between an external manipulated value and the effective
manipulated value is carried out alternatively by
• a binary value from the function block
• a signal that results from the ORing of a binary value from the function block
and a digital input
Tracking input
The following alternative settings are available:
• The tracking input has the value zero
• The tracking input is the conditioned analog value of an analog input
Position feedback input (only step
controller)
The following alternative settings are available:
• The position feedback input has the value zero
• The position feedback input is the conditioned analog value of an analog
input
Switching to tracking
The changeover between the manipulated value and the tracking input is carried
out alternatively
• A binary value from the function block
• A signal that results from the ORing of a binary value from the function block
and a digital input
Switching to safety manipulated value
•
•
•
•
•
Determination of the safety manipulated value
Alternative reaction of the FM 355 during start up:
– The FM 355 goes into closed-loop control operation
– The safety manipulated value is output as the manipulated value
The changeover to the safety manipulated value is carried alternatively by
– A binary value from the function block
– A signal that results from the ORing of a binary value from the function
block and a digital input
Reaction at a measuring transducer fault of Actual value A:
– The operating mode of the controller remains unchanged at the setting
"Closed-loop control operation"
– If the setting is "Manipulated value = Safety manipulated value", the
system changes over to the safety manipulated value
Reaction at a measuring transducer fault of an analog input:
– The operating mode of the controller remains unchanged at the setting
"Closed-loop control operation"
– If the setting is "Manipulated value = Safety manipulated value", the
system changes over to the safety manipulated value
Manipulated value limit
Upper and lower limit (cannot be deactivated)
Generation of the split-range
manipulated values
•
•
•
On/off (only continuous-action controllers)
Starting and end value of input signal
Starting and end value of output signal
Pulse generator (only step controller)
•
•
•
Motor actuating time
Minimum pulse time
Minimum break time
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FM 355 closed-loop control module
Operating Instructions, Edition 02/2006, A5E00059344-03