Curiously, I started fresh, put this back in the pump and it works like a charm.
This went crazy later on (yesterday) but might now know why.

MaxStroke = GetUserDRO (1105)
CutLength = GetUserDRO (1100)
SawKerf = GetUserDRO (1104)
 
SetUserDRO (1107,MaxStroke / (CutLength + SawKerf))
SetUserDRO(1106,Fix(GetUserDRO (1107)))

Almost identical to your's TP, does it need the "If" and the Waits ?

NONE of these DRO's (1100,4 & 5) are moving, like an axis ... they are all fixed user entered values.     

Task: See if you can get a SINGLE line script to do what the 2 lines above do.
This is what I thought I had working yesterday that crapped out on me. My "Simple" sample a few posts back.
Will be back later ........
Russ

Using R3.043.022

Without the check loop it continuously writes the DRO. With the loop IF the value has not changed it just exits saving the time slice of the write.

yes a single line your way or 2 lines my way(checkloop) should work just fine.

(;-) TP

That is about as short as I can get it dependable.

   
SetUserDRO(1106,Fix (GetUserDro(1105)/(GetUserDro(1100) + GetUSerDro(1104))))
While Ismoving()
Wend
End