Hi Richard

In short am I right in thinking if I declare :-

x var byte
readingx var word

Then Substitute :-

x = x + SCALEOFFSET
x = (x MIN LOWRANGE MAX HIGHRANGE) ** SCALEFACTOR - ATNFACTOR

With :-

x = readingx >> 4

The ATN Calculation might work ??

I am away from my desk at moment but have been struggling with this for a whilst..... :-(

BR
Andy