How does IO Link Hub BNI IOL-355-S02-Z013 work in safety function up to SIL2?

Working of IO Link Hub BNI IOL-355-S02-Z013 in safety function up to SIL2

The device is an IO-Link device. It operates 8 digital in- and outputs per IEC 61131-2. The supply voltage of the outputs can be safety switched off by an external safety relay.

The BNI IOL-355-S02-Z013 is suitable for use in safety functions up to SIL 2 (per IEC 61508) and Performance Level d (per ISO 13849).

Fig. 1 shows an example application with a safety function. The safety function of the safe switch-off is implemented using the following signal chain:
Safe switches (e. g. E-Stop) – Safety relay– BNI IOL-355-S02-Z013 – Actuators.

All these elements must be suited for use in this safety function.

The following safety function is achieved here: When the E-Stop is actuated, the actuators are
safely turned off.


In the above fig. Circuit example 1 consisting of a PC, a controller which are connected to an IO Link master. A power supply powers the IO-Link master and - through a safety relay - an IO-Link device (here: BNI IOL-355-S02-Z013). E-Stop or safety light curtains may be connected to the safety relay. Sensors (left) and actuators (right) are connected to the IO-Link device.


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