Mitsubishi Electric MELSEC iQ-R Series Safety Manual page 130

Sequential muting
■Safety application overview
This application temporarily invalidates a shading detection signal such as a light curtain. This application allows carrying
members into a hazardous area without de-energizing a robot.
The muting is controlled with a muting sensor.
This section describes a sequential muting with four muting sensors.
This controls the start and stop of a robot by turning on or off the main contact of the contractor which opens and closes the
power source of a robot.
Connect the light curtain 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.
After completing the previous process, allow the muting and then start carrying members in the hazardous area. In this
procedure, a start of carrying is detected with sensors.
2.
The muting is enabled when the four muting sensors detected works in correct timing and order while the muting is set to
be allowed. The robot is de-energized when detected timing or order is incorrect. For the correct timing and order, and
conditions to start and end the muting, refer to the following.
 MELSEC iQ-R Safety Function Block Reference
Once muting has been started, the second muting operation will be disabled.
3.
Set valid period of muting. If the muting does not end within the set period, it is forcibly terminated and the robot is de-
energized.
4.
A muting lamp is on during the muting so that the workers can easily recognize the muting status. If an error such as
disconnection occurs due to faulty wiring to a muting lamp during muting, the muting is suspended.
5.
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.
6.
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
128
5.1 System Configured by a Safety CPU
Previous
Member
process