Yaskawa YASNAC PC NC Maintenance Manual - Manual (Page 46)

Chapter 4: Troubleshooting PC NC Maintenance Manual
4-25
Figure 4.1: Reference Point Return Control I/O Signals
(d) Parameter setting is incorrect.
Check the setting for the related parameters against the
parameter sheet.
(e) Position of the dog for the deceleration limit switch is incor-
rect. If the dog position is incorrect, the zero point could be
shifted by one turn of the motor.
(f) Others (loose coupling or dog)
If another adjustment is incorrect, zero point could shift at
random.
(6) Cycle Start is Impossible
(a) Cycle start signal is not input or feed hold signal is open.
Determine whether the I/O monitor #3003 D0 is “1” when the
cycle start switch is pressed. In this case, the feed hold signal
must be open; this can be confirmed by I/O monitor #3003
D1 = 1.
(b) Start interlock signal is input.
If I/O monitor #3004 D2 = 1, cycle start is impossible.
(c) The NC is in the reset status.
Normal status: I/O monitor #3500 D1 = 0.
Also check the external reset signal status.
Normal status: I/O monitor #3004 D1 = 0
Deceleration switch signal
(*DCX signal)