Emerson SI-Universal User Manual page 72

1x.042
Minimum
Default
Type
Display Format
Coding
Value
0
1
2
3
4
5
P1 Feedback Filter (1x.042) defines the time period for a sliding window filter that may be applied to
the feedback taken from the drive P1 position feedback interface.
This is particularly useful in applications where the drive encoder is used to give speed feedback for
the speed controller and where the load includes a high inertia and hence the speed controller
gains are very high. Under these conditions without a filter on the feedback, it is possible for the
speed loop output to change constantly from one current limit to the other and lock the integral term
of the speed controller.
1x.043
Minimum
Default
Type
Display Format
Coding
The speed feedback from the P1 position feedback interface can be used as a source to control a
parameter. The speed feedback is scaled to give a value as a percentage of P1 Maximum
Reference (1x.043) in 0.1 % units which is displayed in P1 Reference (1x.045). The value is then
scaled by the P1 Reference Scaling (1x.044) and then routed to the destination defined by P1
Reference destination (1x.046).
Normally the destination is updated every 4 ms, but if the destination is the Hard Speed Reference
(03.022) on the drive, P1 Maximum Reference (1x.043) = VM_SPEED_FREQ_REF[MAX] and P1
Reference Scaling (1x.044) = 1.000 it is updated every 250 µs. Although the hard speed reference
is updated every 250 µs internally a value in rpm or mm/s is written to Hard Speed Reference
(03.022) on the drive every 4 µs for indication only.
The value transferred to the hard speed reference is written in internal units as a change of position
32
in 1/2 revolution units over a time period of 250 µs giving a speed resolution of 55.9 x 10
72
P1 Feedback Filter
0
0
8 Bit User Save
None
RW, Txt
Text
Disabled
1 ms
2 ms
4 ms
8 ms
16 ms
P1 Maximum Reference
0
3000
16 Bit User Save
None
RW, BU
Maximum
Units
Update Rate
Decimal Places
Maximum
Units
Update Rate
Decimal Places
SI-Universal Encoder User Guide
5
Background read
0
50000
Background read
0
-6
rpm.
Issue: 2