5.4 - Safety-related control system performance

Last edit: 11/07/2023

Performance requirements

The minimum performance of the control system related to robot safety must be:

Performance Level (PL) = d, Category 3 as described by ISO 13849-1; or
Safety Integrity Level (SIL) 2, HFT (hardware fault tolerance) = 1, with a “proof test” interval of not less than 20 years, as described by IEC 62061.
This means:

A failure of a safety system component must not cause the loss of the safety function;
The failure must be detected before or at the exact time when the safety function is required to intervene;
When the failure occurs, the safety function must always intervene and a safe condition must be maintained as long as the failure is present;
All foreseeable failures must be detected.
Any failure of the safety control system must result in a category 0 or 1 shutdown as prescribed in IEC 60204-1.