63
Feedback Signals in Open Loop
In some drives, feedback signals and feedback parameters are only
used in closed loop operation. In the VLT 6000, the feedback signals
are also active in open loop operation. Although they don’t effect the
speed of the drive, they can be displayed on the drive’s meters.
Parameters 227 and 228 can set high and low limits for the feedback
signals, which can activate warnings.
For open or closed loop operation, the feedback signal is scaled in
parameters 413 and 414 Minimum and Maximum Feedback, and the
unit displayed is chosen in parameter 415, Process Units.
413
Minimum Feedback
(MIN. FEEDBACK)
Value:
-999,999.999 to Maximum Feedback, Parameter 414
★
0.000
Function:
Parameters 413 Minimum Feedback and 414 Maximum Feedback,
are used to scale the feedback signal.
Description of choice:
Set the value to be shown on the display when the feedbck signal is at
its minimum value.
414
Maximum Feedback
(MAX. FEEDBACK)
Value:
Minimum Feedback to 999,999.999
★
100.000
Function:
See the description of parameter 413, Minimum Feedback.
Description of choice:
Set the value to be shown on the display when the feedback signal is at
its maximum.
415
Units Relating to Closed Loop
(REF. / FDBK. UNIT)
Value:
No unit
[0]
°C
[21]
★
%
[1]
GPM
[22]
rpm
[2]
gal/s
[23]
ppm
[3]
gal/min
[24]
pulse/s
[4]
gal/h
[25]
l/s
[5]
lb/s
[26]
l/min
[6]
lb/min
[27]
l/h
[7]
lb/h
[28]
kg/s
[8]
CFM
[29]
kg/min
[9]
ft
3
/s
[30]
kg/h
[10]
ft
3
/min
[31]
m
3
/s
[11]
ft
3
/h
[32]
m
3
/min
[12]
ft/s
[33]
m
3
/h
[13]
in wg
[34]
m/s
[14]
ft wg
[35]
mbar
[15]
PSI
[36]
bar
[16]
lb/in
2
[37]
Pa
[17]
HP
[38]
kPa
[18]
°F
[39]
m wg
[19]
kW
[20]
Function:
Selects the unit shown on the feedback display.
The selected unit is used if Reference [unit] or Feedback [unit] has
been selected in one of the parameters 007 through 010, as well as in
the Display Mode. It will be the unit for Minimum/Maximum Feedback.
In Closed Loop, the unit is also used as the unit for Minimum/Maximum
Reference and Minimum/Maximum Feedback, as well as Setpoint 1
and Setpoint 2.
Description of choice:
Select the unit for the reference/feedback signal.
✭
Indicates default parameter. Depending upon the application, the drive may be delivered with other parameters selected.
