On large machines and plants, there are usually many safety guards which must be secured to protect the operator from injury. In addition to monitoring these safety guards, each machine must also be safeguarded with one or more emergency stop devices in accordance with the Machinery Directive (MRL). Classically, for cost reasons, the guard monitoring and the emergency stop function are wired in series, but still separately, so that several safety relays are required. With the SMART Safety System from BERNSTEIN, this complex wiring is a thing of the past.
In addition to the SRF (Safety RFID) safety sensors for monitoring the safety guards, the SEU (Safety Emergency Unit) emergency stop devices can also be wired in one and the same safety circuit. Thanks to the patented Daisy Chain Diagnostic System (DCD), extensive diagnostic data of each connected device can be evaluated with the corresponding safety evaluations, such as the SCR P, for example via Ethernet.
With the new illuminated emergency stop device from BERNSTEIN, SEU, this data can no longer be visualised only on an HMI (Human-Machine Interface). The actuated emergency stop device is also quickly visible thanks to the large LED status display. “The otherwise often complex and tedious search for the emergency stop is drastically reduced by the possibility of visual perception directly on the device. Downtimes can be shortened or completely avoided by the clearly visible LED display”, says Paul Sharp, Managing Director of BERNSTEIN Ltd.
Emergency stop devices, in particular, are also exposed to strong mechanical stress. For this reason, they must be replaced after a certain number of actuations. The DCD system allows this number of actuations to be read out easily. This allows the emergency stop to be replaced in good time before the permitted service life is reached (predictive maintenance).
Furthermore, thanks to the self-monitoring OSSD channels, series connection of SMART Safety System components such as SRF and SEU is also possible without any problems, even without taking fault masking (see TR 24119) into account.