Safety gear hooks straight onto AS-i bus

Machine safety specialist Schmersal has developed a range of safety equipment that connects directly to an AS-i fieldbus cable, without needing any intermediate modules. The AS range uses embedded chips to eliminate traditional I/O modules, allowing components such as emergency stops, light curtains, laser scanners and safety switches, to connect directly to AS-i cables.

"But we didn`t stop there," says Terry Hayward, Schmersal`s UK general manager. "We have also revolutionised the operation of the AS interlock switches so that the keys now break light beams instead of mechanical connections."

The first components to be offered with the integrated AS-i interface include a solenoid interlock switch, a magnetic sensor, a pull-wire emergency stop switch, a two-handed control panel, an E-stop station, and a door handle with a built-in pushbutton. Signals from the components are evaluated using a safety monitor recently launched by Schmersal.

New and existing AS-i networks can be expanded to include the new components, which are configured and commissioned using drag-and-drop software and a handheld programming tool. "Engineers simply choose the safety device, connect it to the yellow AS-i cable, set the safety function in the safety monitor, and that`s it," explains Hayward.

The components can be used in safety applications up to category 4 of EN 954-1, and have been tested and approved by the German TÜV standards authority.

Schmersal plans to develop similar components for other open safety bus systems.