RFID technology is now increasingly gaining importance in various sectors of the manufacturing industry. The advantages become apparent when this technology is used in conjunction with devices capable of integrating the related benefits into a new design model of industrial automation using Manufacturing Execution System (MES) software.
Through one of its divisions in Italy, operating in the field of MES, Siemens has taken a leading position in RFID technology utilised for the purposes of industrial automation.
With the Simatic IT MES framework and components infrastructure, the production operation is co-ordinated by a central system for event management, enabling the creation and processing of orders, collection of lots from the warehouse and control and traceability of the processes of automatic and manual assembly. All this is implemented using suitable RFID tags fitted to individual product components or pallets and ‘huts’.
In principle three separate application scenarios for RFID technology can be distinguished in the manufacturing and process industry where the support of MES applications is significant.
1. Where it is impossible to fully meet the requirements for traceability within the plant, because the tags cannot be fitted to every material (eg. liquids in tanks).
2. Integration of production processes within the plant and identify ability of working processes which need to be carried out as part of the legal regulations and quality records.
3. Optimisation of product resources within the plant through precise localisation of materials.
A successful case study using RFID technology with MES systems is a solution implemented by a well known Spanish food group (Grupo Leche Pascual). This solution is based on the tracking of egg pallets supplied to a plant by various farms.
The system Planta De Huevo/Liquid Egg Plant works in the following manner:
* The tags fitted permanently to the transfer cars are reused in a closed cycle creating a permanent link between the tag ID and the car. This dramatically reduces tag costs.
* The cars are loaded with egg pallets from a truck and transported to a station where the weight is checked, then to a station for breaking the shells. In Simatic IT the cars with eggs are modelled like ‘huts’.
The following processes are carried out:
receipt of the eggs from the truck;
loading of a car fitted with a reusable RFID tag;
weighing of the car;
moving the car to the warehouse;
moving and unloading the car to the station for breaking the shells; and
return of the empty car to the warehouse.
All processes are implemented and monitored via two different kinds of events received by Simatic IT and the Production Modeller, the program of the overall application, which manages the events and other components:
* Weighing event when a car with RFID tag enters the weighing station. After this route the car can be sent to the warehouse.
* Breakage event when a car with RFID tag is moved from the warehouse to the station for breaking the shells.
For each individual finished product package with eggs leaving the factory it is possible to query the origin, arrival date, expiry date and other information.
The technology also makes it possible to detect and remove directly in the warehouse area those egg pallets which for any reason have exceeded the intended expiry date.
In future there will be constant further developments of this kind of integration allowing for a considerable reduction in the operating costs, especially with regard to the costs of tags and their reuse, with an ever more progressive functionality designed in accordance with customer requirements.
For more information call Siemens business manager MES, David Berridge, on 07 3332 8323.