Omron NE1A-SCPU01 - 07-2009 Operation Manual page 225

Command Reference: Function Blocks
Note
■
Position Detection
In this application, the workpiece is mounted on a machine turntable sur-
rounded by a guard fence. The operator can disable the light-interruption sig-
nal of the light curtain safety function in order to set a workpiece on the
turntable when he is on the opposite side of the machine's dangerous area.
Block Diagram
Machine's Dangerous Area is on the Operator's Side (Figure 1):
Light curtain
Work platform
Limit switch 2
(N.C. contact)
ON
IN1
Machine's Dangerous Area is on the Opposite Side of the Operator (Figure 2):
Light curtain
Work platform
Limit switch 2
(N.C. contact)
OFF
IN1
In the above example, limit switch 1 is wired to IN0 on the NE1A-series Con-
troller and limit switch 2 is wired to IN1. Set the dual channel mode for local
input in the NE1A-series Controller to dual channel complementary.
Operator
Light curtain
Limit switch 1
(N.O. contact)
OFF
NE1A-series
IN0
Controller
Operator
Light curtain
Limit switch 1
(N.O. contact)
ON
NE1A-series
IN0
Controller
Section 8-5
Guard fence
Guard fence
191