20-20 Feedback Function
Option:
Function:
NOTE
If only two feedback signals are used, the
feedback that is not to be used must be
set to
No Function
in
or
. Note that each
setpoint reference will be the sum of its
respective parameter value (
and
and any other references that are enabled
(see parameter group 3-1*).
[6] Multi
Setpoint
Max
[6] Multi-setpoint maximum
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 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
or
. Note that each
setpoint reference will be the sum of its
respective parameter value (
,
and
and any other references that are enabled
(see parameter group 3-1*).
NOTE
Any unused feedback must be set to “No function” in its
Feedback Source parameter:
,
or
.
The feedback resulting from the function selected in
will be used by the PID Controller
to control the output frequency of the frequency
converter. This feedback can also be shown on the
frequency converter’s display, be used to control a
frequency converter's analog output, and be transmitted
over various serial communication protocols.
20-21 Setpoint 1
Range:
Function:
0
ProcessCtrlUnit
*
[-999999.999 -
999999.999
ProcessCtrlUnit]
Setpoint 1 is used in Closed
Loop Mode to enter a
setpoint reference that is
20-21 Setpoint 1
Range:
Function:
used by the frequency
converter’s PID Controller.
See the description of
.
NOTE
Setpoint reference
entered here is added to
any other references
that are enabled (see
parameter group 3-1*).
20-22 Setpoint 2
Range:
Function:
0
ProcessCtrlUnit
*
[-999999.999 -
999999.999
ProcessCtrlUnit]
Setpoint 2 is used in
Closed Loop Mode to
enter a setpoint reference
that may be used by the
frequency converter’s PID
Controller. See the
description of
Feedback
Function
,
NOTE
The set-point reference entered here is added to any other
references that are enabled (see parameter group 3-1*).
20-23 Setpoint 3
Range:
Function:
0
ProcessCtrlUnit
*
[-999999.999 -
999999.999
ProcessCtrlUnit]
Setpoint 3 is used in Closed
Loop Mode to enter a
setpoint reference that may
be used by the frequency
converter’s PID Controller.
See the description of
NOTE
The setpoint reference
entered here is added to
any other references
that are enabled (see
parameter group 3-1*).
3.15.3 20-3* Feedback Adv. Conversion
In air conditioning compressor applications it is often
useful to control the system based on the temperature of
the refrigerant. However, it is generally more convenient to
directly measure its pressure. This parameter group allows
the frequency converter’s PID Controller to convert
Parameter Description
VLT
®
Refrigeration Drive Programming Guide
MG16H102 - VLT
®
is a registered Danfoss trademark
115
3
3
