Omron VARISPEED E7 User Manual page 253

Square Root Feedback Operation
If parameter b5-28 is set to 1 the feedback value is converted into a value that equals the square root of the
actual feedback. This can be used for example to control the flow rate when a pressure sensor is used to gener-
ate a feedback value. With parameter b5-29 the square root can be multiplied with a factor. Following formula
applies:
So linear connection between the PI target value and the feedback can be realized.
With parameter b5-30 also the feedback monitor can be switched to show a square root value of the actual
feedback.
Scaling of PI Parameters and Monitors with Units
The PI parameter b5-19 and the monitor parameters U1-24 and U1-38 can be scaled using parameter b5-20.
Following setting can be applied:
0:
1:
2 to 39:
40 to 39999: User desired display. Sets the maximum setting displayed using the setting rule in
Example: When the max. PI value should be 200.0, set 12000: 2000 for the maximum display and 1 for the
one digit behind the decimal point
Additional to the scaling also units can be displayed if a Digital Operator with LCD clear text display is used.
The units are defined by parameter b5-31 and following units are available:
Setting
Value
0
1
2
3
4
5
6
7
8
9
10
11
6-96
flow rate = gain (b5-29)
0.01 Hz units (default setting
0.01% (Maximum output frequency is 100%)
rotation per minute (rpm) (Sets the motor poles)
Fig 6.61 PI Scaling Setting Rule
Function
WC: Inch of water column
PSI: lb/square inch
GPM: Gallons per minute
F: Degree Fahrenheit
CFM: Cubic feet per minute
CMH: Cubic meter per hour
LPH: Liters per hour
LPS: Liters per second
Bar: Bar
Pa: Pascal
C: Degree Celsius
Mtr: Meters
×
pressure (head)
Set the display at maximum fre-
quency excluding the decimal
point.
Set the number of digits displayed
the decimal point.
Displayed Unit
WC
PSI
GPM
F
CFM
CMH
LPH
LPS
Bar
Pa
C
Mtr
Fig 6.61