Motion AB - AXIS_VIRTUAL as Feedback Only

Hi,

We are in situation where our absolute master encoder (plugged in to the kinetix 5700 on the universal feedback port) on a new piece of equipment has failed after a week without a backup spare on hand.

The system uses this master axis for camming of infeed system (slave servo) using the MAPC motion block.

We do have a neighboring machine with a different absolute encoder in the same position collecting the same rotary information which we can send to the infeed system using a low RPI.

Is it possible to use this data (0-360 degrees DINT) and provide it to a AXIS_VIRTUAL to then replace the normal axis with the virtual one in the MAPC command? I have tried using the MRP and MAM commands to make the axis match up with the consumed input with no success. It doesn't seem to update the velocity and acceleration properly in the virtual axis. It seems like this would be possible but I'm not sure how to do it. Is anyone able to provide an example of how this might be done.

I have attached an image of our encoder fault as well for clarification.

Simple answer is Don't do it that way

Problems are the slave axis will follow the jerking MAM that you are placing on the virtual axis - the slave CAMs have been designed with the master axis having smooth velocity and acceleration

Best is to replace the encoder

OR
Look to a combined hardware and software solution
Eg replace the absolute encoder with a suitable incremental encoder and use the Other Absolute encoder to define the position before engaging the slave CAMS

Thanks for replying.

I spoke to Rockwell and they seemed to think a MAJ to follow the speed and then window its execution using the position might work instead of a MAM, but there is no way to perfectly pass a REAL/DINT into a AXIS_VIRTUAL.

We ended up flying in a new encoder from another state to get up and running again.