Transparency Enhancer

RFID system BL ident guarantees efficiency during the production of sodium glutamate

A significant Chinese company in the food industry wanted to implement a real-time material management system that allowed the tracing and control of the raw material transfers via RFID technology. The system has to evaluate the information from the warehouse data list and assign the single pallets to material stocks. Then the data is written by a combined read/write head via RFID onto the data carrier that is attached to the pallet.

Next, the PLC automatically assigns warehouse areas to the pallets and guides the forklift to store the materials at the corresponding locations. The forklift, which is also equipped with a combined read/write head, saves the location and the product information in the central system.

To guarantee a high availability, the system is operated with redundancy built in for central and decentralized data. For the outbounding process, the First-In-First-Out (FIFO) principle applies. The system automatically guides the forklift to carry the materials to the corresponding production lines according to the production tasks. During the transport, the read/write head at the forklift checks the data carrier on the pallet to determine if the material is required. If there is an error, the system gives an alarm and automatically indicates what measures need to be taken to restore it.

Digitalized pallets

The RFID tags are already integrated into the pallets. This makes it easy to implement a precise digital management for large quantities of goods. The workers do not need to print lots of bar codes in advance, stick them onto the pallets and scan them with a bar code gun. For the tagged pallets all this takes place during one read/write procedure.

The RFID tags can also be applied in harsh environments. This is because scratches and stains on their surfaces don’t affect them. Tags are recyclable and can be used during rain as well. Additionally the specific tag UID improves the precision of the material tracing.

The production of sodium glutamate takes place under humid production conditions. The powdery raw materials are stored separately from the production. The system has to be able to work perfectly in dry and dusty conditions as well as in a humid environment. That is the reason the company uses Turcks BL67 fieldbus gateways with the RFID module BL ident in IP67. It is attached to the forklift and, due to its IP67 rating, it is able to operate in both environmental conditions. As tradition in the food industry, tags in IP68 are needed because raw materials come into direct contact with the pallets. A BL ident read/write head that is attached to the forklift allows reading and writing to occur during transport.

Wireless forklift connection

The biggest challenge of this project was the connection of the gateways at the forklifts to the controls. After several discussions and experiments, Turck suggested a wireless Ethernet network that allowed the communication between the programmable gateways and the control level.