Reference Handling - Danfoss FC 300 Design Manual

FC 300 Design Guide

Reference Handling

References and feedback can be scaled in physical units (i.e. RPM, Hz, °C) or simply in % relating to the
values of par. 3-02 Minimum Reference and par. 3-03 Maximum Reference.
In that case all analog and pulse inputs are scaled according to the following rules:
• When par. 3-00 Reference Range is [0] Min - Max 0% reference equals 0 [unit] where unit can
be any unit e.g. rpm, m/s, bar etc. 100% reference equals the Max (abs (par. 3-03 Maximum
Reference), abs (par. 3-02 Minimum Reference)).
• When par. 3-00 Reference Range: [1] -Max - +Max 0% reference equals 0 [unit] -100% refer-
ence equals -Max Reference 100% reference equals Max Reference.
Bus references are scaled according to the following rules:
• When par. 3-00 Reference Range is [0] Min - Max. To obtain max resolution on the bus reference
the scaling on the bus is: 0% reference equals Min Reference and 100% reference equals Max
reference.
• When par. 3-00 Reference Range: [1] -Max - +Max -100% reference equals -Max Reference
100% reference equals Max Reference.
Par. 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 are clamped when necessary. The
relation between the resulting reference (after clamping) and the sum of all references is shown below.
The value of par. 3-02 Minimum Reference can
not be set to less than 0, unless the par. 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 ref-
erences is as shown to the right.
Introduction to FC 300
MG.33.B7.02 - VLT is a registered Danfoss trademark
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