Hi,
it doesn't really matter where the home switches are with 'home offset' you can effectively nominate any location as your home or reference position.
When you hit <Ref All> each axis in turn drives until its home switch activates, then it backs off until the home switch deactivates and THEN......
it can do one of two things:
1) It can set the machine co-ordinate for the axis as zero....or
2) It can set the machine co-ordinate as your home offset per your designation.
Imagine you have home switch on your X axis 50mm from the lefthand end. When referencing if you select option 1) above the machine co-ordinate at that
location would be 0. So your X axis can range from -50 at the extreme left to (max-50) at the extreme right. This would work fine but its likely to be confusing,
a reference location that is not in the centre or at either end is not that logical.
You could choose option 2) and nominate your X home offset as 50mm. Under this circumstance when the machine homes the X axis it drives until the home
switch activates as normal but it resets the machine co-ordinates to 50. If you then jogged the axis further to the left the machine co-ords would reduce
until you were at or near the limit switch at the extreme left of the axis at X machine co-ordinate 0. Note that the axis does not drive anywhere unusual or
anything like that it just resets the machine co-ordinate to some value other than 0. This has the effect of saying that the machine zero is 50mm from the
home switch.
May I suggest experimenting a bit. Put some different values in the X home offset on the homing page and watch what happens. Make sure that your DROs
are displaying machine co-ordinates. With some offset see which way and by how much you would have to jog to bring the X axis machine co-ord to zero.
Craig