Danfoss FC 300 Programming Manual page 98

Parameter Descriptions
7-45 Process PID Feed Fwd Resource
Option:
[0] No function
*
3 3
[1] Analog input 53
[2] Analog input 54
[7] Frequency input 29
[8] Frequency input 33
[11] Local bus reference
[20] Digital pot.meter
[21] Analog input X30-11
[22] Analog input X30-12
[32] Bus PCD
7-46 Process PID Feed Fwd Normal/ Inv. Ctrl.
Option:
[0] Normal Select Normal [0] to set the feed forward factor to
*
[1] Inverse Select Inverse [1] to treat the FF resource as a
7-48 PCD Feed Forward
Range:
0 [0 - 65535 ] Read-out parameter where the Fieldbus PCD
*
7-49 Process PID Output Normal/ Inv. Ctrl.
Option:
[0] Normal Select Normal [0] to use the resulting output from
*
[1] Inverse Select Inverse [1] to invert the resulting output from
98
Function:
Select which drive input should be
used as the feed forward factor. The FF
factor is added directly to the output
of the PID controller. This increases
dynamic performance.
Selects a bus reference configured by
Par. 8-02 Control Word Source. Change
PCD Write Configuration for the bus
used in order to make the feed-
forward available. Use index 1 for feed-
forward [748] (and index 2 for
reference [1682]).
Function:
treat the FF resource as a positive value.
negative value.
Function:
feed-forward can be read.
Function:
the process PID controller as is.
the process PID controller. This operation is
performed after the feed forward factor is applied.
MG.33.M9.02 - VLT
FC 300 Programming Guide
3.9.6 7-5* Process PID Ctrl.
7-50 Process PID Extended PID
Option:
[0] Disabled Disables the extended parts of the process PID
[1] Enabled Enables the extended parts of the PID controller.
*
7-51 Process PID Feed Fwd Gain
Range:
1.00 [0.00 -
*
100.00 ]
7-52 Process PID Feed Fwd Ramp up
Range:
0.01 s
*
7-53 Process PID Feed Fwd Ramp down
Range:
0.01 s
*
7-56 Process PID Ref. Filter Time
Range:
0.001 s
*
7-57 Process PID Fb. Filter Time
Range:
0.001 s
*
®
is a registered Danfoss trademark
Function:
controller.
Function:
The feed forward is used to obtain the desired
level, based on a well-known signal available.
The PID controller then only takes care of the
smaler part of the control, necessary because
of unknown characters. The standard feed fwd
factor in par. 7-38 is always related to the
reference whereas 7-51 has more choices. In
winder applications, the feed fwd factor will
typically be the line speed of the system.
Function:
[0.01 - 10.00 s] Controls the dynamics of the feed
forward signal when ramping up.
Function:
[0.01 - 10.00 s] Controls the dynamics of the feed
forward signal when ramping down.
Function:
[0.001 - Set a time constant for the reference first
1.000 s] order low-pass filter. The low-pass filter
improves steady-state performance and
dampens oscillations on the reference/
feedback signals. However severe filtering
can be detrimental to dynamic perform-
ance.
Function:
[0.001 - Set a time constant for the feedback first
1.000 s] order low-pass filter. The low-pass filter
improves steady-state performance and
dampens oscillations on the reference/
feedback signals. However severe filtering
can be detrimental to dynamic perform-
ance.