Commissioning and maintenance


Before the system is taken into use the safety functions must be tested/validated.

The STO-SBC function shall be activated/deactivated and the reactions shall be monitored (the reaction depends if used as emergency stop or prevention of unexpected start-up or something else).

  1. Safety wiring diagrams and the commissioning test shall be documented and stored (who,what,when)

  2. Define maintenance routines according to the need (see chapter maintenance)


IEC 61800-5-2:2017 requires to have a maintenance test for STO-SBC function. The frequency of testing depends on the required safety level:

  • one test per year for SIL 2 , PL d / category 3

  • one test per three months for SIL 3 , PL e / category 3

The maintenance test can be done by activating STO/SBC function through STO-SBC inputs and observe the reaction of the system. The STO/SBC feedback functionality can be used as a part of the maintenance test.