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Implementation of safety requirements from applicable standards

The safety-related function block has been developed according to the safety requirements (from applicable standards) listed in this section. All other requirements from these standards must be observed when implementing the safety-related function.

This section describes either how the function block meets the requirements of the standards or what measures need to be taken to meet the requirements of the standards.

StandardsContext/RequirementImplementation
EN ISO 13849-1Manual reset deviceThe Reset input supports the function of the manual reset device.

Note
Resetting does not occur with a negative (falling) edge, as specified by standard EN ISO 13849-1, but with a positive (rising) edge.
To implement the reset with a falling edge (with regard to the mandatory acceptance procedure), use the safety-related function block SF_Reset.

EN ISO 12100-2Start-up after failure of supply voltage/spontaneous restartThe function block supports

  • a start-up inhibit after the Safety PLC has started up and the function block has been activated.
  • a restart inhibit after the error has been removed, i.e., once a valid combination of the input signals has returned.
If Activate does not indicate the status of the safety-related devices, you must implement this function by other means.
You are responsible for planning and implementing the start-up/restart behavior according to your risk analysis.
To prevent an unintended start-up/restart, you may need to perform an additional operation stop following the removal of the request for the safety-related function. This will depend on both the results of the risk analysis and the signal path of the reset signal.
EN ISO 13849-1Category B to 4Single-channel or two-channel connection must be established depending on the category.

Note
Cross-circuit monitoring is not performed by the function block. It is your responsibility to implement this monitoring function outside of this function block in the safety-related control system. For example, an SF_Equivalent function block must be connected upstream for the purpose of evaluating signals if a two-channel control device with two N/C contacts is used.

EN 60204Stop functionsThe function block (S_SafetyActive enable signal) executes stop category 0.