Yamaha CEmarking RCX221, Supporting Supplement Manual

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Chapter 5 EXTERNAL SAFETY CIRCUIT EXAMPLES
5-1
5.1 External safety circuit examples
This section describes category-specific safety circuit configuration examples using the
RPB-E.
Customers should install the appropriate safety measures for their system by referring to
the circuit example for each controller, in order to use the robots more safely.
5.1.1 Performance level
To comply with the machinery directives, the "performance level (PL)" required of the
safety circuit must be evaluated.
Performance levels (PL) are determined by the following parameters:
●
Major factors that determine performance levels
1. Category
2. MTTFd (Mean Time To Dangerous Failure)
3. DCavg (Average Diagnostic Coverage)
4. CCF (Common Cause Failure)
: Checklist score > 65 ?
(Please obtain the data on each component from the component manufacturer.)
The performance level (PL) of a safety circuit is determined by the following flow.
●
Flow for determining performance levels
1. Determine the "performance level (PLr) required of the safety circuit" by means
of risk assessment.
2. Configure the safety circuit that satisfies the requirements of the category that
meets
PLr.
3. Calculate the safety circuit's "performance level (PL)" from the MTTFd, DCavg,
and CCF of the devices used for the safety circuit, and then make sure that the
calculated PL is equal to or higher than the "performance level (PLr) required of
the safety circuit" (PLr PL).
In the customer's final system, the performance level (PLr) required of the safety circuit
should be determined by means of risk assessment, and then the safety circuit with the
corresponding performance level (PL) should be configured.
5.1 External safety circuit examples