4. REFERENCE POSITION ESTABLISHMENT
B--63003EN--1/02
360
When installing the deceleration limit switch for manual reference
position return, ensure that following conditions are satisfied:
*DEC1
Grid
Feedrate
Rapidtraverserate(V
R
)
Deceleration limit
operation position
FL rate (V
L
)
...... . . . . .
L
DA
L
DW
Reference position
Deceleration limit
release position
D L
DW
: Deceleration dog width (mm or inch)
L
DW
>
V
R
(
T
R
2
+ 30 + T
S
) + 4V
L
× T
S
60 × 1000
V
R
: Rapid traverse (mm/min or inch/min)
T
R
: Rapid traverse time constant (ms)
T
S
: Servo time constant (ms)
V
L
: FL speed for reference position return (mm/min or inch /min)
D L
DA
: Distance between deceleration limit switch released position
and reference position
L
DA:
Move amount of 1/2 revolution of motor
Since the above conditions do not include the limit switch operation
variations, this point must also be considered at installation.
To perform manual reference position return when the reference position
has not yet been established, the tool must be fed, in manual reference
position return mode, in the reference position return direction at a speed
so that the servo position error exceeds the value set in parameter No.
1836. At this time, the tool must cross the grid line corresponding to a
one--rotation signal from the position detector.
The servo position error is calculated from the following formula:
Servo position error amount=
F × 1000
60
×
1
G
×
1
U
F: Feedrate
G: Servo loop gain [s
-- 1
]
U: Detection unit [μm]
(Example)
When the tool is fed at a feedrate F of 6000 mm/min with a servo loop gain
Gof30s
-- 1
and a detection unit U of 1 μm, the servo position error is
calculated as follows:
Servo position error =
6000 × 1000
60
×
1
30
×
1
1
=3,333
Installation conditions
for deceleration limit
switch
Servo position error and
one--rotation signal