Control Loop Configuration - Bosch rexroth EFC 610 Series Operating Instructions Manual

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Functions and Parameters
When E4.05 is set to '1: Negative', then "Feedback- Reference" is used for PID
regulation, which is used when feedback value will drop when output frequency
rises.
E4.05
0: Positive
1:Negative
Tab. 12-25: PID feedback polarity

Control Loop Configuration

Code Name
E4.15 Proportional gain - P
E4.16 Integral time - Ti
E4.17 Derivative time - Td
E4.18 Sampling period - T
Proportional gain - P: Decides the gain of deviation
Larger P means larger scale and faster response, but excessively large P leads
●
to oscillation.
P cannot eliminate deviation completely.
●
Integral time - Ti: Used to eliminate the deviation
Smaller Ti means faster response of the frequency converter to deviation
●
changes, but excessively small Ti leads to oscillation.
If Ti = 0, integration is deactivated during PID control.
●
– Integration stops but the integral value is kept.
– Integration continues if Ti ≠ 0.
Derivative time - Td: Used to respond fast to changes of deviation between refer-
ence and feedback.
Larger Td means faster response, but excessively large Td leads to oscillation.
●
If Td = 0, derivative is deactivated during PID control.
●
Derivative stops and its value is reset to '0'.
Sampling period - T: Sampling time in PID control
The value should match with the selected time constant Ti or Td, normally short-
er than 1/5 of the time constant.
Bosch Rexroth AG R912005854_Edition 09
Rexroth Frequency Converter EFC x610
PID Output
↑
↓
↑
↓
Setting range
0.000...60.000
0.00...100.00 s
(0.00: no integral)
0.00...100.00 s
(0.00: no derivative)
0.01...100.00 s
PID Feedback
Default Unit
1.500 - 0.001
1.50 s 0.01
0.00 s 0.01
0.50 s 0.01
Series
↑
↓
↓
↑
Step Attri.
Run
Run
Run
Run