Mitsubishi Electric MELSEC iQ-R Series Safety Manual page 122

Three-position enabling switch
■Safety application overview
This application controls energization of a robot with the three-position enabling switch while the safety barrier guard is open
for teaching or maintenance of a robot which is performed in the safety barrier. For interlocking the safety barrier and
releasing the interlock during automatic operation, refer to the following.
Page 110 Guard interlock circuit
Start and stop of a robot is controlled by turning on or off the main contact of the contractor which opens and closes the power
source of a robot. Connect the enabling switch, safety switch, and electromagnetic contactors to a safety programmable
controller.
The Safety CPU controls on or off of the electromagnetic contactors with program.
When the safety programmable controller detects an error with the self-diagnostics, outputs to the electromagnetic contactors
turn off independent of the program.
In this case, regardless of the program, the outputs remain off until the Safety CPU or safety remote I/O module is reset.
Configure the program so that the following functions can be achieved.
1.
Switch the operation mode to manual mode so that automatic operation is not allowed. In manual mode, take measures
for safety such as limitation of operation speed of the robot.
2.
In manual mode, operation using except the enabling switch is inhibited.
3.
When the enabling switch is held down in the middle position, the robot is energized. In this case, the robot operation is
independent of status of the safety barrier guard (Even when the guard is open, operation at limited speed is possible).
4.
When a safety electromagnetic contactor is welded, input the electromagnetic contactor (normally closed contact) to the
safety programmable controller to prevent starting, and check for welding.
5.
When an error is detected in the safety remote I/O module after operation starts, outputs to the electromagnetic
contactors turn off.
(Partially quoted from "Safety Guide Book - the safety measures of machinery in the workplace": Nippon Electric Control
Equipment Industries Association)
5 SAFETY APPLICATION CONFIGURATION EXAMPLES
120
5.1 System Configured by a Safety CPU