Hi All
Mick, I did think you still had Kp set at 550. I cannot fault the way you have attempted to optimise tuning of the CSMIO, and if you feel that the axis is performing as well as it originally did, and/or are satisfied with it, so be it.
Out of interest, did you get the CSMIO scope to work, or did you just use the figure for following error? The scope would allow you to see how fast the axis reacts to a step change, and how well damped the resulting transients are.
Like Craig, however, I feel that the velocity loop is weak and this may well be what is preventing the auto-tune completing sensibly as well as rendering your overall manual tune sub-optimal. If you feel inclined to push for better performance, this is the area that I feel needs your attention. You will need a scope, or as I have suggested you could probably use the CSMIO scope if you don't possess one. But if you proceed, do take care not to invoke the position loop as well. You would tune that, repeating the process you've already carried out, after you had optimised the velocity loop. Either use a signal generator to feed the command inputs, or if that is not available, try using Vff (only) with CSMIO as I suggested earlier.
Best of luck if you proceed with it. It might be wise to mark the original position of RV4 just in case you have to revert to the status quo.
Allan