
B-63494EN/02 3.SAFETY FUNCTIONS
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Guard open request signal and guard unlock signal
24V
X
Door open request
Ladder
Ladder
ORQ-I
ORQ
LGD
LGD-O
G
FY
Protective door
CNC (PMC)
The figure shows a sample connection of the protective door open
request switch and the guard unlock signal. In the normal state, the
following state transition takes place before the safety monitoring state
is established.
State transition
ORQ-I ORQ *LGD *LGD-O
A
0 0 0 0 A protective door open request is not made, and the
door is locked.
Normal operating
state
B
1 0 0 0 A guard open request is made.
C
1 1 0 0 The request is transferred to the CNC.
D
1 1 1 0 A safety speed check and a machine position check
prove that there is no failure and that the CNC can
enter the safe state.
E
1 1 1 1 The actual safety door is unlocked.
Operations can be performed with the door open.
Safety function
enabled
D
1 1 1 0 The door is closed and locked again.
F
0 1 1 0 The guard open request is canceled.
G
0 0 1 0 The request is transferred to the CNC.
A
0 0 0 0 The CNC exits from the safe state.
NOTE
1 If the CNC detects that the protective door is open
(SGD is set to 0) while ORQ is set to 0, the CNC
judges that an abnormal event has occurred and
enters the safe stop state. This can occur, for
instance, when the door happens to open (or to be
unlocked) while machining is in progress with the
protective door open
2 When two or more protective doors are installed,
the protective door open request switch and the
protective door lock signal need to be connected for
each protective door.