i load "Z change.tap" to mach3 and it run( i use sheetcam) , then in line 30 , i press "Feed hold" then "Reverse run". Is apparently no problem but issue is Z .
 i see when go reverse, approximately When reach to line 29 . is Z dro changed .
is very bad.this is big problem.
Z dro goto 52 and plasma dont work and dont cut.
Please guide me .

As has been said before, if you are using the demo version then, according to what Art told me, the Reverse Run does not work correctly. Because you are attempting to use Reverse Run that is likely your problem.
Hood

no, reverse run work well