Dead Band Around Zero - Danfoss VLT AutomationDrive FC 300 Design Manual

FC 300 Design Guide

Dead Band Around Zero

In some cases the reference (in rare cases also the feedback) should have a Dead Band around zero (i.e.
to make sure 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 done:
• 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.
The size of the Dead Band is defined by either P1 or P2 as shown in the graph below.
Thus a reference endpoint of P1 = (0 V, 0 RPM) will not result in any dead band, but a reference endpoint
of e.g. P1 = (1V, 0 RPM) will result in a -1V to +1V dead band in this case provided that the end point
P2 is placed in either Quadrant 1 or Quadrant 4.
Introduction to FC 300
®
MG.33.B8.02 - VLT is a registered Danfoss trademark
27