This code can be found in the mpmaster post which I'll just show here for simplicity.   First you need to create a buffer near the top of the post, somewhere around all the variable declarations:   # -------------------------------------------------------------------------- # Buffer 5 - Min / Max # -------------------------------------------------------------------------- b5_gcode : 0 b5_zmin : 0 b5_zmax : 0 rc5 : 2 wc5 : 1 size5 : 0 fbuf 5 0 3 0 0 #Min / Max