As an example, you will no doubt have seen in the Enums and Pound variable lists the specific location/name of
the variable containing the current axis positions. You could read that memory location and get the data. However the
correct way to do so is with the mcAxisGetMachinePos() API. No doubt internal to Mach the API function reads and
returns the same Pound variable. If however the location of that variable changes, say in a more recent build, the code that
you used to read the data direct is now broken whereas the API would still work given that the API would be self consistent
with the new build

I think i understand what you mean, using the API in a sense gives you stronger code less chance of breaking links after updates and with different
system configurations?

An Enum is short for 'enumerator'. For example mc.mcISIG_INPUT4 is actually a number, in fact the number 3, being
the (0, 1, 2) 3rd input. Much easier for humans to remember ISIG_INPUT4 than a plain old '3'. When the code is
compiled the compiler will substitute the number for the Enum, but that detail is not apparent to us for all its importance
to the computer running the code

Feeling like a bit of a greenhorn with this one, should know this abbreviation
nice simple explanation !

I assume you are in Canterbury somewhere? I used to live in Akaroa and had done for many years but have
shifted recently to Selwyn Huts on the shore of Lake Elesmere

haha no i meant nationally local,  grew up in the Coromandel
beautiful down were you are, watch out for flooding

sorry if going off topic with this thread
thanks for all you help