Turbo to Power PSET command (bias position)

[Lobenstein]

I am currently converting one of our machines from turbo to power and am struggling to figure out the bias position setup. In turbo we would bring the machine down to the part and do a "PSET X0 Y0 Z0". This sets positions to 0 so we can then work off position 0 for our operation. When we are finished we return to position 0 then do a PSET command using the part position we were at previously to restore machine actual position. I have been trying to do this in Power by setting the Motor[x].HomePos equal to commanded position to set my positions to 0 and it just is not behaving correctly when running the tool path. I was wondering what the best practice is in PowerPMAC for mimicing the bias position from turbo?

[leandro.martins]

As just an educated guess, to set correctly the Motor[x].HomePos in that case, it's necessary to consider the current HomePos.

Since the queried position on the position window is equivalent to Motor[x].ActPos-Motor[x].HomePos, so setting a position to zero should look like something like
Motor[x].HomePos={commanded position}-Motor[x].HomePos

As far as I know, the PSET also exists for PowerPMAC, that I suppose that does exactly the same operation manipulating the HomePos.

I hope that helps.
 

[steve.milici]

Note that unlike in PMAC and Turbo PMAC, the pset command in the Power PMAC does change the motor zero position, and therefore the frame of reference for the software position limits and the compensation tables. To change the axis programming frame of reference without changing the motor zero, the axis transformation matrices should be used instead.