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Description:
The aim of this project was to build a field distributed control (FDC) based automation system for a pilot flotation tank in laboratory of process control in HUT and to research the possibilities in utilizing digital fieldbus technology in device diagnostics. The goal was to build an automation system similar to commercial Proscon system. The main difference to Proscon system was utilization of digital fieldbus instead of analog 4-20 mA signaling. Fieldbus technology was chosen to be Foundation Fieldbus because it fits well to be used in device diagnostics.
The flotation cell process in our laboratory is a slightly modified version of the Outokumpu TC-3 TankCell. An additional 3.5 m3 tank is used to provide circulation.
The process is equipped with state of the art Foundation Fieldbus instruments. Three digital Neles Automation valve positioners are used to control the cell output valves and air supply valve. Level, flow and pressure measurements are implemented using Smar, Rosemount and Miltronics technology. An Ilmeco flotation air blower and feed circulation pump are controlled by Vacon frequency converters. The fieldbus universal bridge (DFI302) that acts as a link between foundation and ethernet network was also from Smar.
Foundation Fieldbus offers a possibility to use field-distributed control. This means that all the calculation and control actions are made by field devices, not by PLC. This enables a “Plug’n Play” type installation via a standard Ethernet cable into a Outokumpu PROSCON 2100NT Process Management Station without any wiring to the PLC. When system was implemented, an architecture that would be scaleable and modular as possible was aimed. Therefore use of proprietary interfaces was not appropriate. De facto interfaces standarts like OPC and ODBC was used in system integration. System was configured using Syscon 302 from Smar and the user interface software that was used to control the process was GE Fanuc’s Cimplicity. Both of these softwares works via OPC server.
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