Danfoss FC 300 Design Manual page 209

FC 300 Design Guide
Function:
Set a time constant for the speed control low-pass
filter. The low-pass filter improves steady-state
performance and dampens oscillations on the
feedback signal. This is an advantage if there
is a great amount on noise in the system, see
illustration below. For example, if a time constant
(τ) of 100 ms is programmed, the cut-off frequency
for the low-pass filter will be 1/0.1= 10 RAD/sec.,
corresponding to (10/2 x p) = 1.6 Hz. The PID
regulator only regulates a feedback signal that
varies by a frequency of less than 1.6 Hz. If the
feedback signal varies by a higher frequency than
1.6 Hz, the PID regulator does not react.
Note that severe filtering can be detrimental
to dynamic performance.
This parameter is used with par. 1-00 Speed
closed loop [1] and Torque [2] control.
7-2* Process Ctrl. Feedb.
"
Select the feedback sources for the Process PID
Control, and how this feedback should be handled.
7-20 Process CL Feedback 1 Resource
Option:
*
No function
Analog input 53
Analog input 54
Frequency input 29
Frequency input 33
Bus feedback 1
Bus feedback 2
Analog input X30/11
* default setting ( )
How to Program
[0]
[1]
[2]
[3]
[4]
[5]
[6]
[7]
display text [ ] value for use in communication via serial communication port
MG.33.B6.22 - VLT is a registered Danfoss trademark
Analog input X30/12
Function:
The effective feedback signal is made up of the
sum of up to two different input signals.
Select which frequency converter input should be
treated as the source of the first of these signals.
The second input signal is defined in par. 7-22.
7-22 Process CL Feedback 2 Resource
Option:
*
No function
Analog input 53
Analog input 54
Frequency input 29
Frequency input 33
Bus feedback 1
Bus feedback 2
Analog input X30/11
Analog input X30/12
Function:
The effective feedback signal is made up of the
sum of up to two different input signals. Select
which frequency converter input should be treated
as the source of the second of these signals. The
first input signal is defined in par. 7-21.
7-3* Process PID Ctrl.
"
Parameters for configuring the Process PID control.
7-30 Process PID Normal/Inverse Control
Option:
*
Normal
Inverse
Function:
Select Normal [0] to set the process control
to increase the output frequency.
Select Inverse [1] to set the process control
to reduce the output frequency. Normal and
inverse control are implemented by introducing
a difference between the reference signal
and the feedback signal.
7-31 Process PID Anti Windup
Option:
*
Off
On
[8]
[0]
[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]
[0]
[1]
[0]
[1]
209