Danfoss VLT HVAC Basic Drive FC 101 Design Manual page 32

Product Overview
The remote reference is comprised of:
2 2
•
Preset references
•
External references (analog inputs and serial
communication bus references)
•
The preset relative reference
•
Feedback controlled setpoint
Up to eight preset references can be programmed in the
adjustable frequency drive. The active preset reference can
be selected using digital inputs or the serial communi-
cations bus. The reference can also be supplied externally,
most commonly from an analog input. This external source
is selected by one of the three Reference Source
parameters (3-15 Reference 1 Source, 3-16 Reference 2 Source
and 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 two can be selected to be the active
reference. Finally, this reference can be scaled by using
3-14 Preset Relative Reference.
The scaled reference is calculated as follows:
Reference = X + X ×
Where X is the external reference, the preset reference or
the sum of these and Y is 3-14 Preset Relative Reference in
[%].
If Y, 3-14 Preset Relative Reference, is set to 0%, the
reference is not affected by the scaling.
30
Design Guide
Y
100
Danfoss A/S © Rev. 2014-01-14 All rights reserved. MG18C522