Sick has reinvented the lightgrid as a versatile ‘light chain’ of cascading photoelectric sensors. The FlexChain detection system is a completely new way of configuring light grids that offers unprecedented freedom for automated print and packaging machinery applications.
With FlexChain up to 60 sensors can be daisy chained together in a single line topology and connected to a compact FlexChain host. The cost saving ‘mix and match’ concept allows engineers to build their own light grids via a web selection tool and to individually space through beam, reflex and proximity sensors as needed, with minimal cabling and installation. It is easy to add more sensors at a later stage.
Push button commissioning is quick and easy via the FlexChain host and using individual sensors enables a high level of diagnostic information to be available at all times, with maximum detection reliability.
‘Where conventional light grids are limited by fixed send and receive profiles, and multiple sensor arrays require individual cabling and risk cross talk interference if positioned too close together, the FlexChain now offers the best of both worlds,’ explained David Hannaby, UK product manager for presence detection. ‘In addition, a FlexChain can be over 60 metres long – which is very big for a lightgrid.’
He continued, ‘FlexChain is a new way of thinking that offers quicker paybacks for common automated light grid applications in printing, converting and papermaking, such as width classification and leading edge detection in continuous or sheet material feeding, or for materials handling and pallet loading checks.’
The FlexChain system offers the benefits of lightgrid detection with sequential triggering of every beam, but, unlike a conventional lightgrid, positioning the sensors individually makes it possible to vary the beam separation to suit the application. Measuring ranges and detection zones of different widths can be set up for each task.
The system uses modified sensors from the company’s G6 family that are fitted with a special ASIC. Cross talk between sensors is eliminated thanks to the innovativelightgrid technology. Maximum availability is assured irrespective of how the sensors are arranged and how close to, or far away from, each other they are.
The sensors are cabled as a cascade using pigtails in three varying lengths, so cabling costs are much lower than if they were wired individually and installation time is minimised. It is simple to integrate the application specific sensors needed into both new or existing plant and machinery.