NCT Group NCT 990T - Manual (Page 77)

7.2.1 Work Zero Point Offset Measurement
77
Work Zero Point Offset Measurement, if Tool Length Equals to Coordinate Shift
If tool lengths are measured so
that they also contain the offsets
of the work zero point (see tool
length measurement) work off-
sets do not have to be measured.
An exception to this if the offset
needs to be compensated, as well
as if another work coordinate
system is to be used. This is
needed, for the tool length is
calculated in relation to a given
work coordinate system.
The process corresponds to the
above discussed one. The control
calculates the offset amount with
the help of the above-mentioned
equation:
M
x
= x – x
c
– x
0
M
z
= z – z
c
– z
0
However this time the offset of the new coordinate system (G55) is shifted in relation to the
previous one (G54), as seen on the diagram beside.