Scaling Of References And Feedback; Dead Band Around Zero - Danfoss FC 300 Design Manual

FC 300 Design Guide

3.2.10. Scaling of References and Feedback

References and feedback are scaled from analog and pulse inputs in the same way. The only
difference is that a reference above or below the specified minimum and maximum "endpoints" (P1
and P2 in the graph below) are clamped, whereas a feedback above or below is not.
The endpoints P1 and P2 are defined by the following parameters, depending on which analog or
pulse input is used
P1 = (Minimum input value, Minimum reference value)
Minimum reference val-
ue
Minimum input value
P2 = (Maximum input value, Maximum reference value)
Maximum reference val-
ue
Maximum input value

3.2.11. Dead Band Around Zero

In some cases, the reference (in rare cases also the feedback) should have a Dead Band around
zero (in order to ensure that the machine is stopped when the reference is "near zero").
To make the dead band active and to set the amount of dead band, the following
settings must be made:
•
•
The size of the Dead Band is defined by either P1 or P2 as shown in the graph below.
Analog 53 Analog 53
S201=OFF S201=ON
Par. 6-14 Par. 6-14
Par. 6-10 [V] Par. 6-12
[mA]
Par. 6-15 Par. 6-15
Par. 6-11 [V] Par. 6-13
[mA]
Either Minimum Reference Value (see table above for relevant parameter) or Maximum
Reference Value must be zero. In other words, either P1 or P2 must be on the X-axis in
the graph below.
And both points defining the scaling graph are in the same quadrant.
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3. Introduction to FC 300
Analog 54 Analog 54 Pulse Input
S202=OFF S202=ON 29
Par. 6-24 Par. 6-24 Par. 5-52
Par. 6-20 [V] Par. 6-22 Par. 5-50
[mA] [Hz]
Par. 6-25 Par. 6-25 Par. 5-53
Par. 6-21 [V] Par. 6-23 Par. 5-51
[mA] [Hz]
3
Pulse Input 33
Par. 5-57
Par. 5-55 [Hz]
Par. 5-58
Par. 5-56 [Hz]
29