SICK’s LECTOR 620 image-based code reader used in windshield assembly at truck plant
The LECTOR 620 image-based code reader from SICK is playing a key role in the assembly of windshields at a truck plant in Germany.
The code reader is being used to obtain a stable reading of the data matrix code printed on each windshield to enable windshields to be correctly matched to the right truck.
The Daimler truck assembly plant in Wörth, Germany, one of the largest in the world has high cycle times in commercial vehicle production with up to 470 trucks leaving the assembly shop every day. This number translates to one vehicle rolling off the line every three minutes, up to 70,000 different variations and six different production series.
Assembling the windshield is the last step of finishing work for the driver’s cab. To ensure that the right windshield is inserted into the right truck, each windshield has a data matrix code printed on the lower left edge that is read by the LECTOR 620 image-based code reader with integrated red and blue lighting.
Since the windshield is transparent, there is no sufficient contrast between the code and the background. To obtain a stable and process-reliable reading, the technicians from Daimler and SICK decided to install a white plastic surface behind the windshield and the code to provide a good contrast to the data matrix code printed in black. The LECTOR 620 is now able to read the data matrix code.
The LECTOR 620 image-based code reader is used twice in the course of assembly: once when feeding the windshields on the conveyor belt and shortly before the gluing process in the final installation position.
The LECTOR 620 is integrated into the plant control via PROFINET, which transmits both the ‘start reading’ command and the reading results by means of the CDM425 connection module.
For optimum connection of the LECTOR 620 to the Simatic S7 controller, SICK provided a specific function block that facilitates integration of the sensor into the PROFINET environment, thus reducing the commissioning effort.
With the implementation of the LECTOR 620 image-based code reader plus PROFINET, SICK provided Daimler a complete solution, starting with code detection all the way to data transfer in the plant control.
The LECTOR 620 image-based code readers are available from SICK.