Lessons in Traceability

Aug. 16, 2012
Summary: This four-page whitepaper, Expert Guide to Traceability for the Automotive Industry, spells out specific goals for a part traceability program, using a detailed example showing component-level, subassembly, major assembly, final assembly and shipment tracking. Using pictures and text, it discusses barcode marking and reading technology, as well networking and data sharing issues.

Traceability for the automotive industry is a process that documents the genealogy of the parts and subassemblies associated with a specific vehicle or range of vehicles. All of this data can be accumulated and combined into a barcode and marked on the part. Barcode readers then decode the data throughout the part’s lifecycle and reliably transfer the information into an Enterprise Resource Planning (ERP) software system ensuring full traceability for each part of a finished vehicle.

To address full lifecycle traceability, automakers and suppliers permanently mark parts with two-dimensional (2D) codes. 2D codes are used for Direct Part Marking (DPM) applications due to their small size, error correction, and amount of data that can be stored as compared to 1D linear barcodes. DPM codes also help with anti-counterfeiting measures, as they are more difficult to replicate.

2D codes are marked directly on the part using several methods depending upon the material composition, part application, and environmental conditions. Common methods that can withstand harsh automotive manufacturing environments include dot peening, laser marking, inkjet printing, and electro-chemical etching.

Imaging technology is used to read 2D codes, because laser scanners can only read 1D barcodes. There is a wide range of cost-effective, image-based ID readers available.

Traditional serial communications are used in cases where the read data stays “local” to the work cell, or in equipment where you want to connect directly to a PC, PLC (Programmable Logic Controller), or machine controller that may already be handling network communications.

An Ethernet network provides computing systems access to plant floor data and allows intelligent devices such as vision systems and ID readers to share information for tasks such as managing inventory, tracking parts, and automating production line changeovers. Fixed-mount and handheld image-based barcode readers are both now available with true Ethernet connectivity. This allows you to scan barcode data directly to the network of PCs, databases, and PLCs without the need of any special transfer devices on the floor.

Be sure the ID readers that you select support industrial protocols such as:  EtherNet/IP with Rockwell Add on Profile (AOP), Priofinet with Siemens GSD, MC protocol, Modbus/TCP, TCP/IP and FTP. Scalability is also enhanced with Ethernet integration. As ID readers proliferate across your operations, they can be centrally managed, providing a much lower cost-of-ownership.

This white paper was written by Cognex Corporation. Publication Date: 2011

Renee Robbins Bassett, Automation World Managing Editor, edited this white paper abstract.

>> Link to the full version of this white paper

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