To ensure the safety of machines and systems, moveable guards such as doors and guards are monitored with special safety sensors. To avoid having to wire them individually, interfaces or input expansion units are used in which the sensors are connected in series and plugged into the safety controller unit via a single cable. In common interfaces, however, all errors cannot be detected when this cascading process is utilized – which is why the machine can no longer achieve performance level “d” in accordance with safety standard EN ISO 13849-1.
For this reason, elobau has equipped the existing interfaces with “intelligence” in the form of control outputs. This allows each error to be detected with an additional monitoring method even when series connection is applied. Thanks to the electronic monitoring of individual channels, which is possible with the new elobau interface even without the use of a standard PLC, performance level “d” can still be reached. The costs of the new interface and the additional measures are negligible compared to wiring the sensors individually.
The new interface enables the interconnection of up to ten safety sensors to one sensor input of the safety controller unit, which thereby offers the capacity for up to 40 sensors.