67
416
Feedback Conversion (FEEDBACK CONV.)
Value:
★
Linear (LINEAR)
[0]
Square root (SQUARE ROOT)
[1]
Function:
In this parameter, a function is selected which converts a feedback
signal from the process to a feedback value that equals the square root
of the connected signal.
This can be used where regulation of a flow is required and the
feedback is from a pressure sensor (flow is proportional to the square
root of 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 diagram below.
Feedback conversion should not be used if two-zone regulation has
been selected in parameter 417, Feedback Function.
Description:
If Linear is selected, the feedback signal and the feedback value will be
proportional.
If Square root is selected, the drive first takes the sqaure root of the
feedback signal.
417
Feedback Function
(2 FEEDBACK, CALC.)
Value:
Minimum (MINIMUM)
[0]
★
Maximum (MAXIMUM)
[1]
Sum (SUM)
[2]
Difference (DIFFERENCE)
[3]
Average (AVERAGE)
[4]
Two-zone minimum (2 ZONE MIN)
[5]
Two-zone maximum (2 ZONE MAX)
[6]
Function:
This parameter sets the calculation method whenever two feedback
signals are used.
Please note that Setpoint 1 is added to the remote reference when
Minimum, Maximum, Sum, Difference or Average is selected.
Description of choice:
If Minimum is selected, the drive will compare Feedback 1 with Feed-
back 2 and regulate on the basis of the lower feedback value.
Feedback 1 = Sum of parameter 537, Bus Feedback 1, and the
feedback signal value of terminal 53.
Feedback 2 = Sum of parameter 538, Bus Feedback 2, and the
feedback signal value of terminal 54.
If Maximum is selected, the drive will compare Feedback 1 with
Feedback 2 and regulate on the basis of the higher feedback value.
If Sum is selected, the drive will total Feedback 1 with Feedback 2.
Please note that Setpoint 1 will be added to the remote reference.
If Difference is selected, the drive will subtract Feedback 1 from
Feedback 2.
If Average is selected, the drive will calculate the average of Feedback
1 and Feedback 2. Please note that Setpoint 1 will be added to the
remote reference.
If 2-zone Minimum is selected, the drive will calculate the difference
between Setpoint 1 and Feedback 1 as well as Setpoint 2 and
Feedback 2. The drive will regulate its output speed based on the
larger difference. A positive difference, (a setpoint higher than the
feedback), is always larger than a negative difference.
If 2-zone Maximum is selected, the drive will calculate the difference
between Setpoint 1 and Feedback 1 as well as Setpoint 2 and
Feedback 2.
After the calculation, the drive will use the smaller difference. A negative
difference (a setpoint lower than the feedback) is always smaller than a
positive difference.
✭
Indicates default parameter. Depending upon the application, the drive may be delivered with other parameters selected.