HEIDENHAIN SW 548328-05 DIN Programming - Manual (Page 447)

HEIDENHAIN MANUALplus 620, CNC PILOT 620/640
447
5.3 T
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o-point measur
ement
Two-point measurement G19 longitudinal G778
Cycle G778 measures two opposite points in the Y/Z plane with the
measuring axis Y
. If the tolerance values defined in the cycle are
exceeded, the cycle saves the measured deviation either as tool
compensation or as an additive compensation. The result of the
measurement is saved additionally in the variable #i99 (See "Touch
probe cycles for automatic operation" on page 431.).
Cycle run
From the current position the touch probe moves along the defined
measuring axis toward the measuring point. When the stylus touches
the workpiece, the measured value is saved and the touch probe is
positioned back to the starting point. For the pre-positioning for the
second measurement, the cycle first moves the touch probe by the
offset in the circumnavigation direction RB and then by the offset in the
measuring direction RC. The cycle executes the second probing
operation in the opposite direction, saves the result and positions the
touch probe back with the circumnavigation axis by the
circumnavigation value.
The control outputs an error message if the touch probe does not
reach any touch point within the defined measuring path. If a
maximum deviation WE was programmed, the measuring points are
approached twice and the mean value is saved as result. If the
difference of the measurements is greater than the maximum
deviation WE, the program run is interrupted and an error message is
displayed.
Example: G778—Two-point measurement for tool
compensation
. . .
MACHINING
N3 G778 R1 K20 YE30 BD0.2 Y40 BE0.3 WT5
Q0 P0 H0
. . .
Parameters
R Type of compensation:
 1: Tool compensation DX/DZ for turning tool or additive
compensation
 2: Recessing tool Dx/DS
 3: Milling toolDX/DD
 4: Milling tool DD
K Incremental measuring path with direction (signed): Maximum
measuring path for probing. The algebraic sign determines the
probing direction.
RB Circumnavigation direction offset: Distance in circumnavigation
direction X
RC Offset Y: Distance for pre-positioning before the second
measurement
ZE Nominal value for target position Y: Absolute coordinate of
touch point
BD Tolerance +/-: Range for the first measurement result in which
no compensation is applied
Z Nominal width Y: Coordinate for the second probing position
BE Tolerance width +/-: Range for the second measurement result
in which no compensation is applied