LGS series light grids – Touch it, save it

Intelligent switching automation light grid with lots of extras

The new LGS series light grids from Pepperl+Fuchs, which stand out due to their slim housing profile and control unit already integrated into the receiver module, are particularly suitable for standard tasks in warehousing and material handling, packaging and in automation in general. The systems cover a detection area of infrared light beams with a field height of up to 3,200 mm and are available with resolutions of 8, 17, 25, 50 and 100 mm parallel beam distance. Additional operation modes significantly simplify typical automation needs and enable new detection solutions. Three separate height switching outputs control height and tension checks. Object identification allows detection of objects via their geometry, which can also contain gaps and openings. A new touch field with illuminated pictograms permits step-by-step programming without a PC. The fast object detection is also not delayed by activation of the 3-way beam crossover. The latter doubles the resolution on average. Further features include optional low temperature versions for -30 to +60 °C, and equipped with IO-Link as well as standby mode.

A new LGS series light grid from Pepperl+Fuchs, which stands out due to its slim housing profile and control unit already integrated into the receiver module, is particularly suitable for standard tasks in warehousing and material handling, packaging and in automation in general. The developers have equipped it with a range of notable functions that were previously only found in much more expensive device classes. This includes the lightning speed signal evaluation even during beam crossover, the possibility of identifying objects, optional low temperature versions and the IO-Link interface.

To complete presence, overhang or height checks or counting and similar routine tasks in product flow and logistics, a light grid is frequently used. They are available in different sizes and with different radiances, and are suitable for a variety of tasks for large and small objects, packages, packaging units, pallets etc. For standard applications, the user needs low-cost, reliable and long-lasting technology that is easily adapted to the requirements of the application. Powerful detection technology combined with intelligent microprocessor evaluation does not stop sensor manufacturers from incorporating ever more interesting functions and ingenious extras, almost as a free bonus, even into lower price category devices.

Light grids for automation

The new LGS series light grids are cost-effective devices incorporated into a particularly compact aluminum housing with a cross-section of 20 x 30 mm and optimized for typical tasks in factory automation. The modular systems from Pepperl+Fuchs consist of a transmitter and a receiver strip which cover a detection area of infrared light beams with a field height of up to 3,200 mm. Resolutions of 8, 17, 25, 50 and 100 mm parallel beam distance are available. The receiver module already contains all electronic components so no separate control interface unit is required. In the simplest configuration and with dark on, the switching output activates if an object is found in or enters the monitoring field and at least one light beam is interrupted.

Integrated object identification

The developers have implemented additional operation modes for some repeated tasks which significantly simplify automation in many situations and enable new detection solutions in customer applications. Light grids are equipped with three separate height switching outputs for frequent height and tension checks. After the corresponding reference points have been taught in, they are therefore able to detect or report three height profiles. Moreover, objects can then not only be detected, but also identified via their geometry. Due to flexible teach-in options, such as inverted teach-in, not only solid objects are identifiable, but also those with gaps and openings, e.g. body components in the automotive industry. Object identification operates at a standstill and for moving objects.

The LGS series stands out due to its extremely fast object detection or beam evaluation. The response time is a mere 6 ms at an evaluation of 100 beams. It is noteworthy that there are no time losses, even when beam crossover is activated. The light grids support three-way beam crossover, i.e. three adjacent channels are scanned simultaneously: that is the parallel beam, preceding and following beams. On average, double resolution is attained without any additional costs.

Touch it, save it – Innovative operating concept via a touch field

All these functions can be activated by pressing a few buttons, without relying on external support or software. In the receiver unit, there is an innovative touch field which has two touch buttons and a range of illuminated pictograms. It enables step-by-step programming without a PC, where the different setting options are moved through quickly and easily using the menu and OK buttons. One touch of a button is enough to teach in an object for identification. In this way, height information and object positioning can be taught in. In the event of unfavorable mounting conditions which interfere with components and are constantly in the detection field, the beams affected can simply be deactivated with the aid of the blanking function.

Low temperature versions rationalize food logistics

Further features of the light grid include optionally available low temperature versions equipped with IO-Link as well as standby mode. For deep freeze applications, e.g. in the food industry, light grids in special versions are available with a suitability for ambient temperatures of -30 to +60 °C instead of -10 to +60 °C. All versions have transmitter and receiver units and their own temperature-stabilization.

IO-Link today qualifies the light grids for future networking strategies. Communication via IO-Link alternatively permits the devices to be operated manually or advanced functions to be configured, such as remote parameterization and online diagnosis. The LGS light grids are joining an ever increasing range of IO-Link sensors from Pepperl+Fuchs.

Standby mode is of interest for applications where the light grids are not used in continuous operation. It is activated by applying continuous voltage to the test input of the transmitter. This not only reduces power consumption, but also protects the transmitter LEDs and increases the service life of the device.

From flexible mounting to automatic signal calibration

The aluminum housing fulfills IP67 degree of protection. The extruded, tinted front panel is correspondingly securely sealed. An innovative quick-tighten mounting bracket is available for simple mounting and quick replacement of the light grid. They permit mounting on all three sides of the profile, based on the Plug & Play principle, without tools. A continuous M6 groove offers further flexible mounting options. Lateral transverse holes for customer-specific mounting can also be made. Because the light grids have two synchronous beams, one top and one bottom, they can be operated from two sides; the top/bottom alignment plays no role, which increases flexibility. The switching mode is configurable to light or dark on. The effective operating distance of the LGS series is 0.2 to 6 m as standard and optionally with an increased distance of 0.4 to 8 m. The signal strength is constantly corrected during operation to compensate for influences from temperature changes or effects from soiling.

Summary

With a variety of operating modes, from switching only to virtually measuring sensors, the new LGS light grids cover all important standard applications in areas such as warehousing and material handling, packaging and logistics. The application possibilities extend from presence and overhang checking for pallets, meshed containers and transport systems, to measuring, sorting and counting tasks, height and tension checking of web-like materials to position and shape monitoring via the identification of objects. The devices can be configured and taught-in either manually without support and software via a touch field, or controlled remotely via IO-Link.