Danfoss VLT FC 100 Series Programming Manual page 143

Parameter Description
20-20 Feedback Function
Option:
3 3
[4] Maximum
[5] Multi
Setpoint
Min
[6] Multi
Setpoint
Max
3-116
VLT
Function:
NOTE!
Any unused feedbacks must be set to No
Function in 20-00 Feedback 1 Source,
20-03 Feedback 2 Source, or 20-06 Feedback
3 Source. Only setpoint 1 will be used. The
sum of Setpoint 1 and any other
references that are enabled (see parameter
group 3-1*) will be used as the PID
controller's setpoint reference.
Maximum [4] sets up the PID controller to com
Feedback 1, Feedback 2 and Feedback 3 and
use the highest value as the feedback.
NOTE!
Any unused feedbacks must be set to No
Function in 20-00 Feedback 1 Source,
20-03 Feedback 2 Source, or 20-06 Feedback
3 Source.
Only Setpoint 1 will be used. The sum of
Setpoint 1 and any other references that are
enabled (see parameter group 3-1*) will be used
as the PID controller's setpoint reference.
Multi-setpoint minimum [5] sets up the PID
Controller to calculate the difference between
Feedback 1 and Setpoint 1, Feedback 2 and
Setpoint 2, and Feedback 3 and Setpoint 3. It
will use the feedback/setpoint pair in which the
feedback is the farthest below its corresponding
setpoint reference. If all feedback signals are
above their corresponding setpoints, the PID
Controller will use the feedback/setpoint pair in
which the difference between the feedback and
setpoint is the least.
NOTE!
If only two feedback signals are used, the
feedback that is not to be used must be
set to No Function in 20-00 Feedback 1
Source, 20-03 Feedback 2 Source or
20-06 Feedback 3 Source. Note that each
setpoint reference will be the sum of its
respective parameter value (20-21 Setpoint
1, 20-22 Setpoint 2 and 20-23 Setpoint 3)
and any other references that are enabled
(see parameter group 3-1*).
Multi-setpoint maximum [6] sets up the PID
Controller to calculate the difference between
Feedback 1 and Setpoint 1, Feedback 2 and
MG11CD22 - VLT
®
HVAC Drive Programming Guide
20-20 Feedback Function
Option:
NOTE!
Any unused feedback must be set to "No function" in its
Feedback Source parameter: 20-00 Feedback 1 Source,
20-03 Feedback 2 Source or 20-06 Feedback 3 Source.
The feedback resulting from the function selected in
20-20 Feedback Function will be used by the PID controller
to control the output frequency of the adjustable
frequency drive. This feedback can also be shown on the
adjustable frequency drive's display, be used to control an
adjustable frequency drive's analog output, and be
transmitted over various serial communication protocols.
The Adjustable frequency drive can be configured to
handle multi-zone applications. Two different multi-zone
applications are supported:
•
Multi-zone, single setpoint
•
Multi-zone, multi setpoint
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Function:
Setpoint 2, and Feedback 3 and Setpoint 3. It
will use the feedback/setpoint pair in which the
feedback is farthest above its corresponding
setpoint reference. If all feedback signals are
below their corresponding setpoints, the PID
Controller will use the feedback/setpoint pair in
which the difference between the feedback and
the setpoint reference is the least.
NOTE!
If only two feedback signals are used, the
feedback that is not to be used must be
set to No Function in 20-00 Feedback 1
Source, 20-03 Feedback 2 Source or
20-06 Feedback 3 Source. Note that each
setpoint reference will be the sum of its
respective parameter value (20-21 Setpoint
1, 20-22 Setpoint 2 and 20-23 Setpoint 3)
and any other references that are enabled
(see parameter group 3-1*).