B–63505EN/02
7.TROUBLESHOOTING
261
Reference position return was executed when the following condition is
not satisfied:
The CNC received one rotation signal at least one time when the axis is
moving to the reference position at a speed higher than a speed equivalent
to 128 pulses of position error amount(DGN300).
(START)
Check whether position gain is greater than 128 pulses
(DGN 300) before or during reference position return.
128 or more
Position error
amount : 300
Check feed rate command:
PRM 1420 F : Rapid traverse rate (mm/min)
PRM 1424 Manual rapid traverse rate (mm/min)
PRM 1825 G : Servo loop gain (0.01sec–1)
F 5000/3
Position error=
G detection unit[µm/PLUSE]
Detection unit : Move amount to a command pulse (usually 1µm)
In metric machine, if the no. of digits below decimal point is 4 on the position
display screen, detection unit is 0.1 µm.
Check rapid traverse override signals :
ROV1 G014.0
ROV2 G014.1
PRM 1421 Fo rate
Check reference position return deceleration signal
*DEC1 to DEC4 : X1009.0 to X1009.3
When reference position return is started from deceleration signal 0, feed rate
becomes FL rate.
PRM 1425 FL rate
ROV1 ROV2
00
01
10
11
YES
NO
(1) Next page
Override
100%
50%
25%
Fo rate
Raise the speed
7.9
ALARM 90
(REFERENCE
POSITION RETURN
IS ABNORMAL)
Contents
Countermeasures