Default implementation of the FROM and GOHOME comand is that the position is defined in sensor co-ordinates, which is why your GOHOME moves relative to the reference sphere.

We currently have a non-standard DMIS command supported in the LK-DMIS 5.0 and 5.0e versions which allows you define an un-calibrated sensor which means that you when you select it you will be in machine co-ordinates from the scale datum

To define this sensor use the following syntax:

S(label)=SNSDEF/NONE,INDEX,POL,a,b

To select it use SNSLCT/S(label).

When you select this sensor, it will rotate to the a,b angles you defined but will restore any calibration data, therefore your datum will be the machine datum.

If you select this probe, then define a FROM the GOHOME should work.

Note, the SNSDEF/NONE is unique to LK. At some time in the future we wil be implementing the DMIS V3.0 syntax of SNSLCT/S(label) and SNSLCT/SA(label). S(label) is nominal probe and SA(label) is calibrated probe. If you are familiar with CMES these two commands are similar to PH\a\b and UR,n,PH.

Pls e-mail me or post a message if you need urther clarification.