Renishaw NC1 Programming Manual page 32

Beam alignment
RENC[3] Z-axis beam alignment error
over the measured span.
(This is empty if the Z-axis is
the beam axis.)
If the R02=1 input is used, the following outputs are also set:
RENT[20] Provisional Z-axis position of the beam when measured
from the positive side of the beam.
RENT[22] Provisional X or Y-axis position of the beam when
measured from the positive side of the beam.
RENT[23] Provisional X or Y-axis position of the beam when
measured from the negative side of the beam.
RENT[24] Provisional position along the beam axis at which the
tool is measured.
Z
(RENC[23] = 3)
30
RENT[20]
RENT[23]
Y (RENC[22] = 2)
X (RENC[21] = 1)
Z+
X+
Y+
RENT[22]
RENT[24]
P2
P1
+ error