Does anyone have a working example of scaling (G51) on a 15M? I have tried every conceivable permutation without success. It simply ignores the block.

Of course if I enter my scaling P value as decimal is complains so I know the block is being read. I assume P0.5 is P500?

I tried this:
%
O1001
G54G90G00X0Y0
G51X0.0Y0.0I500J500K1000
G01X1.0F6.
G50
M30
%

I've also tried:
G51X0.0Y0.0P500
G51I0.0J0.0P500

I've been tinkering with this for a few days and just cannot get it to take it.