Reference Limits - Danfoss VLT AutomationDrive FC 360 Design Manual

Product Overview
The remote reference is calculated once every scan
interval and initially consists of 2 types of reference
inputs:
1. X (the external reference): A sum (see
3-04 Reference Function) of up to 4 externally
selected references, comprising any combination
(determined by the setting of 3-15 Reference 1
Source, 3-16 Reference 2 Source and 3-17 Reference
3 Source) of a fixed preset reference (3-10 Preset
Reference), variable analog references, variable
digital pulse references, and various serial bus
references in any unit the frequency converter is
monitoring ([Hz], [RPM], [Nm] etc.).
2. Y (the relative reference): A sum of one fixed
preset reference (3-14 Preset Relative Reference)
and one variable analog reference (3-18 Relative
Scaling Reference Resource) in [%].
The 2 types of reference inputs are combined in the
following formula: Remote reference=X+X*Y/100%. If
relative reference is not used, set 3-18 Relative Scaling
Reference Resource to [0] No function and 3-14 Preset
Relative Reference to 0%. The catch up/slow down function
and the freeze reference function can both be activated by
digital inputs on the frequency converter. The functions
and parameters are described in the VLT
FC 360 Programming Guide.
The scaling of analog references is described in parameter
groups 6-1* Analog Input 53 and 6-2* Analog Input 54, and
the scaling of digital pulse references is described in
parameter group 5-5* Pulse Input.
Reference limits and ranges are set in parameter group

3-0* Reference Limits.

MG06B402
Design Guide
2.4.1 Reference Limits
3-00 Reference Range, 3-02 Minimum Reference and
3-03 Maximum Reference together define the allowed range
of the sum of all references. The sum of all references is
clamped when necessary. The relation between the
resulting reference (after clamping) and the sum of all
references is shown in Illustration 2.17 and Illustration 2.18.
P 3-00 Reference Range= [0] Min-Max
P 3-03
P 3-02
-P 3-02
®
AutomationDrive
-P 3-03
Illustration 2.17 Sum of All References When Reference Range
is Set to 0
P 3-03
-P 3-03
Illustration 2.18 Sum of All References When Reference Range
is Set to 1
The value of 3-02 Minimum Reference cannot be set to less
than 0, unless 1-00 Configuration Mode is set to [3] Process.
In that case, the following relations between the resulting
reference (after clamping) and the sum of all references is
as shown in Illustration 2.19.
Danfoss A/S © 09/2014 All rights reserved.
Resulting reference
Forward
Reverse
P 3-00 Reference Range =[1]-Max-Max
Resulting reference
2
Sum of all
references
Sum of all
references
23
2