Reading value of pin in g code

How many do you have?

Maybe
And so on.

There aren't any changes... still programme stops at 4 line. I picked 3 times (DEBUG, #5399) before if.

It can't be stopping at line 4. It is executing line 8.

just my two cents
but for me, i noticed when i tried to describe variables or use any of them i need to put them in this format
#<_variable>
or they won't work, IE maybe if you try
#<_4> = 0

(fyi i'm using nightly builds / pre releases as well and installed from the DVD image.)

LinuxCNC supports two sorts of parameters (what might be called variables in an actual programming language, which G-code probably isn't).

#4 is a conventional mumerical parameter
#<myvariable> is a named parameter, an extension to the G-code standard supported by LinuxCNC
#<_myvariable> is a named paramter with global scope (which means that it has a value which can be used outside of the subroutine it is defined in)
#<4> is a named parameter. It will not necessarily have the same value as #4
#<_4> is another named parameter with global scope. It can have a different value to both #4 and #<4>

and my idea does nothing lol, sorry just spit balling thought it was a issue with values/params not communication inside...