Safety Data
These PFD
avg
and PFH calculations are based on the equations from Part 6 of EN 61508 and show worst-case values.Safety Data for Safe Torque Off
These values apply when Safety Instance is set to ‘Safe Stop Only – No Feedback’.
Attribute | Frames 1…7 | Frame 8 | Frame 9 | Frame 10 |
|---|---|---|---|---|
PFD avg | 4.08E-5 | 1.81E-4 | 2.73E-4 | 3.64E-4 |
PFH (1/hour) | 4.77E-10 | 2.09E-9 | 3.14E-9 | 4.19E-9 |
MTTF D years | 204.1 (high) | 93.3 (high) | 69.1 (high) | 55.1 (high) |
DC avg % | 97.5% (medium) | 97.4% (high) | 97.5% (high) | 97.5% (high) |
HFT | 1 (1oo2) | 1 (1oo2) | 1 (1oo2) | 1 (1oo2) |
Mission time | 20 years | 20 years | 20 years | 20 years |
Attribute | Frames 5 and 6 | Frames 7 and 8 | Frame 9 | Frame 10 | Frame 11 | Frame 12 | Frame 13 | Frame 14 | Frame 15 |
|---|---|---|---|---|---|---|---|---|---|
PFD avg | 4.49E-5 | 2.56E-4 | 2.82E-4 | 3.08E-4 | 3.34E-4 | 3.60E-4 | 3.86E-4 | 4.38E-4 | 4.90E-4 |
PFH (1/hour) | 5.24E-10 | 2.96E-9 | 3.25E-9 | 3.55E-9 | 3.85E-9 | 4.15E-9 | 4.45E-9 | 5.05E-9 | 5.65E-9 |
MTTF D years | 187.5 (high) | 102.6 (high) | 87.8 (high) | 76.7 (high) | 68.1 (high) | 61.2 (high) | 55.6 (high) | 47 (high) | 40.7 (high) |
DC avg % | 97.4% (high) | 97.0% (high) | 97.0% (high) | 97.0% (high) | 97.0% (high) | 96.9% (high) | 96.9% (high) | 96.9% (high) | 96.9% (high) |
HFT | 1 (1oo2) | 1 (1oo2) | 1 (1oo2) | 1 (1oo2) | 1 (1oo2) | 1 (1oo2) | 1 (1oo2) | 1 (1oo2) | 1 (1oo2) |
Mission time | 20 years | 20 years | 20 years | 20 years | 20 years | 20 years | 20 years | 20 years | 20 years |
Attribute | Frames 1…7 |
|---|---|
PFD avg | 4.12E-05 |
PFH (1/hour) | 4.81E-10 |
MTTF D years | 202.2 |
DC avg % | 97.5 (high) |
HFT | 1 (1oo2) |
Mission time | 20 years |
Safety Data for Safe Feedback
Use these values with the PFD
avg
or PFH values above for safety functions that require safe encoder feedback. Safety functions using safe encoder feedback include drive based Monitored Safe Stop 1 and controller-based safety functions SS1, SS2, SOS, SLS, SLP, and SDI.When using Dual Feedback Monitoring, enable Discrepancy Testing.
Attribute | Single Encoder Feedback SIL 2/PLd (Category 3) | Dual Encoder Feedback (Dual channel values apply with discrepancy checking configured) SIL 3/PLe (Category 4) |
|---|---|---|
PFD (average) | 6.75E-4 | 4.32E-5 |
PFH (1/hour) | 7.70E-9 | 4.93E-10 |
MTTF D years | 1446.7 (high) | 1427.7 (high) |
DC avg % | 90.0% (medium) | 99.0% (high) |
HFT | 1 (1oo2) | 1 (1oo2) |
Mission time | 20 years | 20 years |
The safe motion-monitoring option can be configured for single feedback or dual feedback to achieve the following safety rating:
- Single feedback configurations provide up to SIL 2 PLd capability.
- Dual-feedback configurations provide up to SIL 3 PLe capability when discrepancy testing (either velocity, position, or both) is enabled.
IMPORTANT:
Achievable safety rating depends on each system component. For Safe Feedback, the safety rating of the selected encoders may limit the safety rating of the system.
Safety Data for Safety I/O
The Integrated Safety Functions option module provides four safety inputs and two safety outputs.
Attribute | Single Channel Safety I/O SIL 2/PLd (Category 2) | Dual Channel Safety I/O SIL 3/PLe (Category 4) |
|---|---|---|
PFD (average) | 3.35E-4 | 2.49E-4 |
PFH (1/hour) | 3.83E-9 | 2.84E-9 |
MTTF D years | 1064.9 (high) | 1998.0 (high) |
DC avg % | 96.4% (high) | 94.2% (high) |
HFT | 0 (1oo1) | 1 (1oo2) |
Mission time | 20 years | 20 years |
IMPORTANT:
Single channel safety I/O is only certified for use in functional safety applications with process safety times greater than or equal to 300 ms; or applications with demand rates less than or equal to 1 demand per 30 second
If single channel safety I/O is used, pulse testing (external pulse testing for safety inputs, pulse testing for safety outputs) MUST be enabled on the single channel I/O points.
Spurious Trip Rate
The Spurious Trip Rate (STR) and Mean Time to Failure Spurious (MTTF Spurious) values for the Integrated Safety Functions option module are calculated according to the ISA TR- 84 method.
Attribute | Value |
|---|---|
Spurious Trip Rate | 3.00E-6 |
MTTFSpurious (years) | 37.0 |
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