Redundant/Custom Feedback

Knowledge Base: Examples Programming
1

Redundant feedback can be implemented in the RMC by using Custom Feedback. When the controller detects that one transducer has problems, it can immediately switch to another feedback on the fly, even in the middle of motion. The user has the flexibility to program the logic that determines which feedback should be used, making redundancy using any number of transducers possible.

Attached is an example project that demonstrates redundant feedback. This involves creating a user program that calculates a custom feedback value each loop time, using one of selected feedback devices. Therefore, you should make sure that the RMC starts in RUN mode and that the user program will always run.

The attached project, together with the Redundant Feedback topic in RMCTools, will get you up and going quickly.

Custom Feedback requires firmware version 3.54.0 or newer.
RedundantFeedback.rmcproj (41.4 KB)

Custom Feedback can be used for many other applications such as:

  • Controlling to the sum, difference, or average of feedback devices such as position or force
  • Switching feedback
  • Feedback linearization
  • Redundant feedback
1 Like
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Hi,
I used the program with custom feedback to implement a notchfilter on a pressure analog input signal (program taken from the forum). In my case I want to control the pressure on the axis but I experience oscillations in a particular frequency region. Here i got to the problem that I’m not allowed to write to the _Axis[0].ActPrs register. as you don’t have the _Axis[0].CustomCounts register to write to for a pressure controlled axis.

Reading the help advised me to implement dual loop axis, but it seems this is not possible without an AP2-card?

Is there any possibility to implement the notchfilter with an RMC75E/AA2/A2
My project with axis configuration below:

Thanks in advance
C10288P01_DemoAHP_WithNotchFilter.rmcproj (21.6 KB)

3

If your axis is defined with custom input, it should work to write to _Axis[0].CustomCounts.

On the attached project, it is defined that way. So you can use CustomCounts as shown below.
image

4

Hi Paul,

Thank you!
I interpreted the CustumCounts register was only usable for position feedback.