•
•
•
•
1.
Speed open
loop
mode
Input command:
freeze reference
Process
control
Scale to
Hz
Scale to
process
unit
Remote
reference/
setpoint
±200%
Feedback
handling
Remote
reference in %
maxRefPCT
minRefPct
min-max ref
Freeze
reference &
increase/
decrease
reference
±100%
Input commands:
Speed up/speed down
±200%
Relative
reference
=
X+X*Y/100
±200%
External reference in %
±200%
Parameter choise:
Reference resource 1,2,3
±100%
Preset reference
Input command:
preset ref bit0, bit1, bit2
+
+
Relative scalling reference
Intern resource
Preset relative reference
±100%
Preset reference 0 ±100%
Preset reference 1 ±100%
Preset reference 2 ±100%
Preset reference 3 ±100%
Preset reference 4 ±100%
Preset reference 5 ±100%
Preset reference 6 ±100%
Preset reference 7 ±100%
External resource 1
No function
Analog reference
±200 %
Local bus reference
±200 %
Pulse input reference
±200 %
Pulse input reference
±200 %
Pulse input reference
±200 %
External resource 2
No function
Analog reference
±200 %
Local bus reference
±200 %
External resource 3
No function
Analog reference
±200 %
Local bus reference
±200 %
Y
X
e3
0b
e8
42
.1
0
Illustration 21: Block Diagram Showing Remote Reference
The remote reference consists of:
Preset references.
External references (analog inputs and serial communication bus references).
The preset relative reference.
Feedback-controlled setpoint.
Up to 8 preset references can be programmed in the drive. The active preset reference can be selected using digital inputs or the
serial communications bus. The reference can also be supplied externally, most commonly from an analog input. This external
source is selected by 1 of the 3 reference source parameters (
parameter 3-15 Reference 1 Source
,
parameter 3-16 Reference 2 Source
,
and
parameter 3-17 Reference 3 Source
). All reference resources and the bus reference are added to produce the total external refer-
ence. The external reference, the preset reference, or the sum of the 2 can be selected to be the active reference. Finally, this refer-
ence can by be scaled using
parameter 3-14 Preset Relative Reference
.
The scaled reference is calculated as follows:
Reference
=
X
+
X
×
Y
100
Where X is the external reference, the preset reference or the sum of these and Y is
parameter 3-14 Preset Relative Reference
in [%].
If Y,
parameter 3-14 Preset Relative Reference
, is set to 0%, the reference is not affected by the scaling.
3.2.8 Tuning the Drive Closed-loop
Once the drive's closed-loop controller has been set up, test the performance of the controller. Often, its performance may be ac-
ceptable using the default values of
parameter 20-93 PI Proportional Gain
and
parameter 20-94 PI Integral Time
. However, sometimes
it may be helpful to optimize these parameter values to provide faster system response while still controlling speed overshoot.
3.2.9 Adjusting the Manual PI
Procedure
Start the motor.
AJ363928382091en-000101 / 130R0983 | 29
Danfoss A/S © 2021.04
Product Overview
VLT® Flow Drive FC 111
Design Guide