72
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 square 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]
Feedback 1 only (FEEDBACK 1 ONLY)
[7]
Feedback 2 only (FEEDBACK 2 ONLY)
[8]
Function:
This parameter determines the calculation method for two feedback
signals. Terminals 53 and 54 are both read in selections [0] through
[6]. In each case, if only one feedback signal is received, a zero value
will be calculated for the inactive terminal. To read feedback from only
one of the two terminals, use
Feedback 1 Only
(terminal 53) or
Feedback 2 Only
(terminal 54) to exclude the inactive terminal.
Feedback 1 =
Sum of parameter 535,
Bus Feedback 1,
(if present) and
the feedback signal value of terminal 53.
Feedback 2 =
Sum of parameter 536,
Bus Feedback 2,
(if present) and
the feedback signal value of terminal 54.
Description of choice:
If
Minimum
is selected, the drive will compare
Feedback 1
with
Feedback 2
and regulate on the basis of the lower feedback value.
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
.
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
.
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.
If
Feedback 1 Only
is selected, terminal 53 is read as the feedback
signal and terminal 54 ignored.
Feedback 1
is compared to
Setpoint 1
for drive control.
If
Feedback 2 Only
is selected, terminal 54 is read as the feedback
signal and terminal 53 ignored.
Feedback 2
is compared to
Setpoint 2
for drive control.
NOTE
Value of parameter 418
, Setpoint 1,
is added to
any remote reference when
Minimum
,
Maximum
,
Sum
,
Difference
or
Average
is
selected.
TR1 drive
✭
I
ndicates factory default setting. Numbers in brackets [ ] represent selection as displayed on the serial bus.