Rockwell Automation 20B PowerFlex 70, PowerFlex 700 Reference Manual - Manual (Page 34)

Analog Outputs
34 Rockwell Automation Publication PFLEX-RM001H-EN-P - June 2013
Filtering
Software filtering will be performed on the analog outputs for certain signal
sources, as specified in
Table 1 . “Filter A” is one possible such filter, and it is
described later in this section. Any software filtering is in addition to any
hardware filtering and sampling delays.
Table 1 Software Filters
Analog output software filters are specified in terms of the time it will take the
output of the filter to move from 0% to various higher levels, given an
instantaneous step in the filter input from 0% to 100%. The numbers describing
filters in this document should be considered approximate; the actual values will
depend on implementation.
Filter A is a single pole digital filter with a 162ms time constant. Given a 0% to
100% step input from a steady state, the output of Filter A will take 500ms to get
to 95% of maximum, 810 ms to get to 99%, and 910 ms to get to 100%.
PowerFlex 700 Firmware 3.001 (& later) Enhancements
Certain analog output enhancements have been included in firmware version
3.001 (and later) for the PowerFlex 700 Vector Control drive. These include:
•
Ability to scale the analog outputs
•
Connect scale blocks to the analog outputs
•
Analog Output controlled via Datalink
Output Scaling
A new scaling feature has been added to allow scaling. Prior to this feature,
[Analog Outx Lo] and [Analog Outx Hi] limited only the voltage. This voltage
range was scaled to the selected option range listed in [Analog Outx Sel]. With
the new feature, [Analog Outx Lo] and [Analog Outx Hi] still set the voltage
range, but the scaling parameter now scales the range of the [Analog Outx Sel]
selection. See the following example.
Quantity Filter
Output Frequency No extra filtering
Commanded Frequency No extra filtering
Output Current Filter A
Output Torque Current Filter A
Output Flux Current Filter A
Output Power Filter A
Output Voltage No extra filtering
DC Bus Voltage Filter A
PI Reference No extra filtering
PI Feedback No extra filtering
PI Error No extra filtering
PI Output No extra filtering