Requirements for operation

• Operation is permitted only within the limits specified in the corresponding documentation. This principle applies to the external safety controller as well as to the device and any approved options.
• The built-in diagnostic function is limited in the case of a permanently enabled or permanently disabled STO input. Advanced diagnostic functions are performed only upon a level change of the STO signal. This is why the STO input of the device must be requested with connected line voltage at least once every 12 months for PL d in accordance with ISO 13849‑1 and SIL 2 IEC 61800-5-2 and at least once every 24 hours for PL e in accordance with ISO 13849‑1 and SIL 3 IEC 61800‑5‑2 to achieve complete test coverage. For this purpose, the test sequence described in the chapter "Cyclic test of the STO inputs" must be observed.

[1]	Maximum 12 months for PL d/SIL 2 Maximum 24 hours for PL e/SIL 3
[2]	Internal diagnostics
[3]	High: No STO
[4]	Low: STO active