
B–64113EN–1/01
4. REFERENCE POSITION ESTABLISHMENT
269
If a correct reference mark interval cannot be detected for a cause, the tool
is positioned to the end point without establishing the reference position.
Therefore, the machine position, absolute coordinates, and machine
coordinates of the end point are set as if a G00 command without reference
position establishment operation were executed. However, the
intermediate tool path is different from the tool path obtained by
executing the G00 command.
Since the reference position is not established, reference position
establishment operation is performed again when the next G00 command
is specified.
Even when the CNC detects an illegal reference mark interval, it does not
issue the P/S090 alarm.
If the following conditions are satisfied, reference position establishment
operation is performed automatically:
<1> For an axis for which no reference position has been established,
feed axis direction selection signal +Jn or –Jn (G100, G102) is input
in jog mode.
<2> The move direction in <1> above matches the reference position
return direction set by bit 5 (ZMI) of parameter No. 1006.
<3> The specified axis is not in the following modes:
S Coordinate system rotation
S Mirror image (mirror image by signal or setting)
S Programmable mirror image (M series)
S Scaling (M series)
S Mirror image of facing tool posts (T series)
NOTE
If all the above conditions are not satisfied, reference
position establishment operation is not performed, and the
same operation as normal jog feed is performed.
The reference position establishment procedure is explained below.
<1> When the feed axis direction selection signal is set to 1, the tool starts
moving at the reference position return FL feedrate (parameter No.
1425).
<2> Upon detection of a reference mark on the scale, the tool is stopped
briefly then fed at the reference position return FL feedrate.
<3> Step <2> above is repeated until three or four reference marks are
detected on the scale. Then, the reference position is established,
and the reference position established signal (ZRF1, ZRF2, ZRF3,
etc.) is set to 1.
<4> The tool is fed in the direction selected by the feed axis direction
selection signal at the jog feedrate.
When the feed axis direction selection signal is set to 0 during steps <2>
to <4>, feed operation stops. When the feed axis direction selection signal
is set to 1 again, the reference position is established.
D When an illegal
reference mark interval
is detected
Reference position
establishment by jog
feed
D Activation condition
D Operation