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Safety Function Capability
PDS (SR) safety functions are part of an overall system
If the qualitative and quantitative safety objectives determined by the final application require some
adjustments to help ensure safe use of the safety functions, the integrator of the BDM (Basic Drive Module)
is responsible for these additional changes (for example, managing the mechanical brake on the motor).
Also, the output data generated by the use of safety functions (activation of the digital input set to
[Operating State Fault], error codes or information on the display, etc.) is not considered to be a safety-
related data.
Machine Application Function Configuration
Process Application Function Configuration
Summary Of The Reliability Study
Preventive annual activation of the safety function is recommended.
However, the safety levels can be obtained (with lower margins) without annual activation.
For the machine environment, a safety module is required for the STO function.
NOTE: The table above is not sufficient to evaluate the PL of a PDS. The PL evaluation has to be done at
the system level. The system integrator has to evaluate the random integrity as well as the systematic
integrity at system level according to IEC61508, IEC 62061, ISO13849 or applicable product standard.
Standard STO
IEC 61800-5-2 / IEC 61508 SIL3
IEC 62061 (1) SIL3 CL
ISO 13849-1 (2) Category 3 PLe
IEC 60204-1 (3) Category stop 0
(1) Because the IEC 62061 standard concerns integration, this standard distinguishes the overall safety
function (which is classified SIL3) from components which constitute the safety function (Altivar Process
is one component which is classified SIL3 CL).
(2) According to table 3 of ISO 13849-1 (2015).
(3) If protection against supply interruption or voltage reduction and subsequent restoration is needed
according to IEC 60204-1, a safety module type Preventa XPS AF or equivalent must be used.
Standard STO
IEC 61800-5-2 / IEC 61508 SIL3
IEC 62061 SIL3 CL
Standard Input ATV630 ATV650
ATV660 ATV680
IEC 61508 Ed.2 SFF 90.2%
PFH in /h
4 x 10
-10
PFD
2 x 10
-6
Type A
HFT 1
T1 (proof test interval) in hours 8760
SIL capability 3
IEC 62061 SIL CL capability 3
ISO 13849-1 (1) PL e
Category 3
MTTFd in years 5000 (2)
DC avg 90%
(1) According to table 4 of EN 13849-1 (2008)
(2) According to ISO13849, the MTTFd has to be reduced to 100 years.