14
Setup mode
Abbé error
Calibrate axis
Calibration parameters are found under Setup mode > Select axis. There
are two options:
•
Calibrate axis
•
Apply Compensation
The Calibrate axis menu offers two modes of compensation:
•
Linear Compensation {
l.comp
}.
•
Segmented Compensation {
s.comp
}.
If you set the axis to Segmented Error Compensation, or Linear Error
Compensation, then your next set up option is to configure the
compensation for that axis.
If you apply Error Compensation, then you must ensure that it is
absolutely correct. If it is not correct, then errors could be increased rather
than reduced.
Once you have set up the Error Compensation, we advise you to check its
effect in normal operation.
Linear compensation
A linear error occurs between the measuring device and the part to be
measured, if the axis is not truly parallel with the encoder scale axis. You
can overcome this by applying a scaler to the measured axis value before
it is displayed. You calculate the correction factor, and specify it in parts
per million (ppm). The values can be between -9999 and +9999.
The DP900 has an automatic facility to calculate the linear error correction
scalar.
All displayed values are in mm, regardless of whether the DP900 is set to
inch or mm mode.
1.
Move to the start position.
2.
Zero the display value by pressing {
reset
}.
3.
Move a known distance (use a laser interferometer, slip gauge or
standard).
4.
Select 'Slip Value' and enter this known distance using the numeric
keypad.
5.
Select 'Cal Factor' and press {
calc
}.
The DP900 calculates and displays a scalar compensation value.
A
B
C2
C2
B2
A2
B1
C1
B1
A1
C1
A1
greater than
End Effector
Linear
encoder
Encoder
End Effector
Linear
encoder
Encoder
less than
encoder
Shown with encoder on
concave
side of
bearing path
Shown with encoder on
convex
side of
bearing path
Error
Travel
