Mitsubishi Electric MELFA CR800 Series Instruction Manual page 15

The following table shows the safety performance of the CR860 controller.
Function
STO Safety Level
Mean time to dangerous failure
(MTTFd)
Diagnostic coverage (DC)
Probability of dangerous failure
per hour (PFH) (Note 2)
Hardware Fault Tolerance
Mission time
Diagnostic test interval
Systematic capability
Safety Level
Mean time to dangerous failure
(MTTFd)
Diagnostic coverage (DC)
Probability of dangerous failure
per hour (PFH) (Note 2)
Hardware Fault Tolerance
Mission time
Diagnostic test interval
Systematic capability
SS1, SS2, Safety Level
SOS, SLS,
SLP
Mean time to dangerous failure
(MTTFd)
Diagnostic coverage (DC)
Probability of dangerous failure
per hour (PFH) (Note 2)
Hardware Fault Tolerance
Mission time
Diagnostic test interval
Systematic capability
Note 1: To use this product at a performance level of SIL 3, Category 4, PL e, refer to "4.6.1 Test pulse diagnosis
(EMG)".
Note 2: The robot controller PFH or PFHd (Probability of Dangerous Failure per Hour).
Note 3: For systems using the I/O signals of the safety extension unit, add the PFH value in the table below.
Safety performance of the safety extension unit complies with PL d/Category 3.
MTTFd
[year]
256
Item
SIL 3 (IEC 61508:2010)
Category 4, PL e
(EN ISO 13849-1:2015)
MTTFd ≥ 100 years
DC = 99%
PFH = 1.60 × 10
1
20 years
1000ms
SC3
SIL 2 (IEC 61508:2010)
Category 3, PL d
(EN ISO 13849-1:2015)
MTTFd ≥ 100 years
DC = 96%
PFH = 2.24 × 10
1
20 years
1000ms
SC2
SIL 2 (IEC 61508:2010)
Category 3, PL d
(EN ISO 13849-1:2015)
MTTFd ≥ 100 years
DC = 95%
PFH = 5.58 × 10
1
20 years
1000ms
SC2
DC
[%]
90
1 FUNCTIONS AND CONFIGURATION
Description
-8 [1/hour]
-8 [1/hour]
-7 [1/hour]
PFH
[1/hour]
1.76 × 10 -8
Remarks
Performance when:
• External emergency
stop input when the test
pulse diagnosis settings
are enabled (Note 1)
Performance when:
• External emergency
stop input when the test
pulse diagnosis settings
are disabled (factory
settings)
• Door switch input
• Enabling device input
• Safety extension unit's
safety input (Note 3)
(Note 3)
Specifications 1-5