Danfoss VLT 8000 AQUA series Operating Instructions Manual page 140

1 setpoint and 1 feedback
If only 1 setpoint and 1 feedback signal are used,
parameter 418 Setpoint 1 will be added to the remote
reference. The sum of the remote reference and
Setpoint 1 becomes the resulting reference, which will
then be compared with the feedback signal.
1 setpoint and 2 feedbacks
Just like in the above situation, the remote reference
is added to Setpoint 1 in parameter 418. Depending
416 Feedback conversion
(FEEDBACK CONV.)
Value:
Linear (LINEAR)
Square root (SQUARE ROOT)
Function:
In this parameter, a function is selected which
converts a connected feedback signal from the
process to a feedback value that equals the square
root of the connected signal.
This is used, e.g. where regulation of a flow (volume)
is required on the basis of pressure as feedback signal
(flow = constant x √pressure). This conversion makes it
possible to set the reference in such a way that there
is a linear connection between the reference and the
flow required. See drawing in next column.
Feedback conversion should not be used if
2-zone regulation in parameter 417 Feedback
function has been selected.
= factory setting. () = display text [] = value for use in communication via serial communication port
140
VLT
on the feedback function selected in parameter
417 Feedback function, a calculation will be made
of the feedback signal with which the sum of the
references and the setpoint is to be compared. A
description of the individual feedback functions is
given in parameter 417 Feedback function.
2 Setpoints and 2 feedbacks
Used in 2-zone regulation, where the function selected
in parameter 417 Feedback function calculates the
setpoint to be added to the remote reference.
Description of choice:
If Linear [0] is selected, the feedback signal and
the feedback value will be proportional.
If Square root [1] is selected, the frequency converter
[0]
translates the feedback signal to a square root value.
[1]
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8000 AQUA