YRC ser
ies
2-14
2
3. External safety circuit examples
This section describes category-specific safety circuit configuration examples using the PB.
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.
3.1
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.
●
Safety parts subject to performance level calculation
The table below shows the safety parts and B10d reference values.
CAUTION
Please obtain the latest information from the parts manufacturers.
Parts name
Model name
Maker
B10d
PB
Emergency stop button
XA1E-BV302R
IDEC
1x10
5
Enable switch
HE2B-M200PB
IDEC
1x10
5
