Emerson SI-Universal User Manual page 112

If P2 Auto-configuration Select (2x.041) = 1 then P2 Comms Baud Rate (2x.037) is set to the
minimum value that will give a total message transfer time of less than 62 μs, so that the transfer
will occur at the fast update rate with the minimum baud rate. It should be noted that the value of P2
User Comms Enable (2x.067) is taken into account as this may affect the message time.
Once these parameters have been set up it should be possible for the drive to operate correctly
with the encoder. The drive repeatedly attempts to initialize the encoder, including auto-
configuration which is part of this process, until it is successful.
Therefore if auto-configuration has not been successful by the time the drive is enabled because
the drive cannot establish communications, an Encoder Setup Changed trip occurs.
For BiSS* encoders the drive must identify the encoder model number to perform auto-
configuration. If communications is established, but the drive cannot recognise the encoder model
an Encoder Type Not Recognized trip is produced immediately.
If auto-configuration is disabled (i.e. P2 Auto-configuration Select (2x.041) = 1) then none of the
above actions are carried out except for the line delay measurement.
P2 Device type (2x.038): All other device types
P2 Auto-configuration Select (2x.041) has no effect.
2x.042
Minimum
Default
Type
Display Format
Coding
Value
0 Disabled
1 1 ms
2 2 ms
3 4 ms
4 8 ms
5 16 ms
P2 Feedback Filter (2x.042) defines the time period for a sliding window filter that may be applied to
the feedback taken from the drive P2 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 high inertia and subsequently 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.
* BiSS is not currently supported.
112
P2 Feedback Filter
0
0
8 Bit User Save
None
RW, Txt
Text
Maximum
Units
Update Rate
Decimal Places
SI-Universal Encoder User Guide
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