
4. REFERENCE POSITION ESTABLISHMENT
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(1)Select JOG mode or TEACH IN JOG mode, and the manual reference
position return selection signal ZRN to “1”.
(2)Feed a target axis toward the reference position by setting an
appropriate feed axis and direction selection signal (+J1, –J1, +J2,
–J2,…) “1”.
(3)While the feed axis and direction selection signal is “1”, rapid traverse
takes place along that axis. Although the rapid traverse override
signals (ROV1, ROV2) are valid, the override is generally set to
100%.
(4)When the reference position is approached, a limit switch installed on
the machine is activated, making the deceleration signal (*DEC1,
*DEC2, *DEC3,…) for reference position “0”. Consequently, the
feedrate is decelerated to 0, then the tool is fed at a constant low speed
(reference position return FL feedrate specified by parameter (No.
1425) setting).
(5)When the deceleration signal returns to “1” again after the limit switch
is passed, the tool is continues to feed, until the tool stops at the first
grid point (electric grid point).
(6)Upon confirmation that the current position is at the in–position area,
the reference position return end signal (ZP1, ZP2, ZP3,…) and the
reference position establishment signal (ZRF1, ZRF2, ZRF3,…) turn
to “1”.
These steps are repeated for each axis. The number of simultaneously
controlled axes is usually one, but it becomes three by setting parameter
JAX (No. 1002#0).
If the feed axis direction selection signal (+J1, –J1, +J2, –J2,…) turns to
“0” between step (2) and (4) , the tool is stopped at once, and reference
position return is canceled. If the signal turn to “1” again, operation
resumes from step (3) (rapid traverse).
The timing charts for the basic procedures are given below.
ZRN
+J1
*DEC1
Grid
ZP1
ZRF1
Feedrate
Rapid traverse rate
FL rate
. . . . . . . . . . . . . . . . . . . . .
JOG or TEACH IN
JOG mode
Basic Procedure for
Manual Reference
Position Return