Reference Handling - Danfoss VLT Micro Drive FC 51 Design Manual

Product Overview

3.1.4 Reference Handling

Details for open-loop and closed-loop operation.
Intern resource
3 3
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%
Extern resource 1
No function
Analog reference
±200 %
Local bus reference
±200 %
LCP potmeter 0~100 %
Extern resource 2
No function
Analog reference
±200 %
Local bus reference
±200 %
LCP potmeter 0~100 %
Extern resource 3
No function
Analog reference
±200 %
Local bus reference
±200 %
LCP potmeter 0~100 %
Illustration 3.4 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
frequency converter. 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 reference. The external reference, the preset
reference, or the sum of the 2 can be selected to be the
20
®
VLT Micro Drive FC 51
Relative scalling reference
Input command:
preset ref bit0, bit1, bit2
Preset reference
±100%
Y
Relative
reference
X
Parameter choise:
+
X+X*Y/100
Reference resource 1,2,3
±200%
+
±200%
External reference in %
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Input command:
freeze reference
maxRefPCT
=
±200%
minRefPct
min-max ref
±100%
Freeze
reference &
increase/
decrease
reference
Input commands:
Speed up/speed down
active reference. Finally, this reference can by be scaled
using parameter 3-14 Preset Relative Reference.
The scaled reference is calculated as follows:
Reference = X + X ×
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.
Speed open
loop
Con guration
Scale to
mode
Hz
Process
control
Scale to
process
unit
±200%
Feedback
handling
Remote
reference in %
Y
Remote
reference/
setpoint
MG02K402