The IJK describes the axis of the probe tip (the surface normal direction of the plane this probe would be ideally suited to measure).
The probe axis is shown relative to the current alignment axis. If, for example, you change your alignment so that +X travels straight up (replacing +Z) your probe IJK value will now be 1,0,0. The first IJK value is usually perfect because you are in the machine alignment.
The Angle is a 2D angle as seen from the alignment Z axis (I think). The reference axis is the X direction and CCW is positive. When you align a part that is not sitting perfectly flat in the machine volume your probe will appear to be pointing slightly in some direction in the XY plane and this is what the angle is trying to describe.
The first tip will only be perfect if it is your master tip. That being said, if you ALWAYS SAY the tool has moved (and I do mean ALWAYS) then the probe file you have open is your master probe file, and IF you always say YES IT HAS MOVED, then the first tip is what Pcdmis uses to LOCATE the qual-sphere. So, it will be perfect to the math build. The other angles are calculated FROM that 'perfect tip', that is where the XYZ offset values come from, and those are used to calculate the IJK values.
