Measurement (M5)
13.4 Measurement accuracy and functional testing
Turning, Milling, Nibbling
Function Manual, 11/2012, 6FC5397-1CP10-5BA0
253
13.4
Measurement accuracy and functional testing
13.4.1
Measuring accuracy
Accuracy
The propagation time of the measuring signal is determined by the hardware used. The
delay times are in the µs range plus the probe response time.
The measurement uncertainty is calculated as follows:
Measurement uncertainty = measuring signal propagation time x traversing velocity
Correct results can only be guaranteed for traversing velocity where not more than one
triggering signal arrives per position controller cycle.
13.4.2
Probe functional test
Example of functional test
The functional test for the probe is conducted favorably via an NC program.
%_N_PRUEF_MESSTASTER_MPF
;Testing program probe connection
N10 R10
;Flag for trigger status
N20 R11 MESSWERT_IN_X
N30 T1 D1
; Preselect tool offset for probe
N40 ANF: G0 G90 X0 F150
;Starting position and meas. velocity
N50 MEAS=1 G1 X100
; Measurement at measuring input 1 in the X
axis
N60 STOPRE
N70 R10=$AC_MEA[1]
; Read switching signal at 1st measuring
input
N80 IF R10==0 GOTOF FEHL1
;Evaluation of signal
N90 R11=$AA_MW[X]
;Read in measured value in workpiece
coordinates
N95 M0
N100 M2
N110 FEHL1: MSG
; Probe not switching!
N120 M0
N130 M2
Example of repeat accuracy
This program allows the measuring scatter (repeat accuracy) of the entire measuring system
(machine-probe-signal transmission) to be calculated.
In the example, ten measurements are taken in the X axis and the measured value recorded
in the workpiece coordinates.