Many years ago, dEE developed the InfraScan, which is widely used in wood processing. Subsequently, a measuring light grid for automation technology in the classic mechanical engineering industry environment and now, as a crowning achievement, the RapidoScan.
After we realized that there are still hardly any products between the simplest light barriers and the more complex laser scanners, we have completely redeveloped the RapidoScan, a very powerful light curtain.

In short, the RapidoScan is by far the fastest measuring light curtain on the market. The RapidoScan requires only 5µs for the evaluation of a single beam. If it is configured so that, for example, only 10 beams are activated, it operates at 20,000 measurements per second, available at the switching output! If an application consists of several single light barriers, or a single light barrier to be re-positioned in height, the reduced wiring effort, the much faster object detection and the availability of fieldbus-specific additional information (alarms, status information, …) with the light grid can result in an interesting alternative. The general immunity to ambient light of the measuring principle results in simplified setups around the measurement.

High resolution
The RapidoScan is offered in lengths from 160mm to 2000mm in increments of 160mm. The light grid has a very high resolution of 2.5mm in parallel beam mode, with activation of an oblique beam mode the resolution can be increased to 1.25mm.

EtherCAT interface, further Ethernet-based interfaces will follow quickly
Via a directly integrated real-time capable Ethernet interface (with integrated hub) all measurement data can be forwarded to the controller. The EtherCAT interface listed in the enclosed data sheet is only the start. A Modbus TCP interface is about to be completed and allows inexpensive and easy coupling to Siemens controllers. Further Ethernet based IRT compatible fieldbus systems will follow as well (POWERLINK should be available by E09/15).

Integrated web server for visualization, WLAN
The RapidoScan has an integrated web server, which allows simple visualization as well as parameterization (notebook or tablet via web browser).

Single beam information
Typical measurement results include data such as FIB, LIB, … or, in the case of the Infrascan, block information such as “Position and Size of Largest Block” was output. The RapidoScan can also provide free/interrupted information from each beam and measurement. In the longest version (1920mm), the RapidoScan has 800 diodes, in oblique beam mode this results in 1599 beams! Each 8 beams are bundled over one byte, which in this case results in almost 200 bytes of process data.
The process data can be configured via a mapping, so the abundance of measurement data is an option and not a must.

Applications in wood processing

Log measurement
The light curtain we developed before – Infrascan – has already been used in some log measuring systems.

Checking the dimensions of an edging AFTER the turning fixture
The RapidoScan can give you a simple statement whether e.g. a cantling with the dimensions 203 x 206mm has actually been turned. The advantage of the light grid over laser measurements is that they do not require image processing via a PC, but the data can simply be made available as a measured value in the PLC.

Detecting the diameter of logs BEFORE the debarker
Recording the log diameter before the debarker helps to preset the appropriate diameter. Primitive control can then be performed during debarking. In this case, the advantage is that the light grid data can be used directly in the PLC without much pre-processing.

Checking the distance between tree trunks
It is popular to keep the distance from one tree trunk to the next small. Detecting the gap between two tree trunks requires a fast measurement. In addition, the measurement must take place at several positions, since a measurement at one position does not provide any real information. The RapidoScan needs only 5µs scanning time per beam and can therefore monitor a measuring range of 1000mm within 2ms (5µs * 400 beams). At a feed rate of 120m/min, the log moves by 4mm in this time!

Line scan camera for simple log measurements
If no complex image evaluation is required, the RapidoScan can also replace a line scan camera. The light grid can be mounted in two planes and by synchronizing the two systems, mutual interference can be avoided.