The growing number of AIB Bakery franchises countrywide prompted the franchiser to erect a fully automated flour milling, premix manufacturing and packaging facility in Mount Edgecombe to supply these bakeries with premix. NC Automation Engineering were awarded the entire automation and electrical contract of the green fields project involving the full automation of the following aspects.

ü      Wheat intake and transfer

ü      Cleaning and tempering

ü      Wheat Milling

ü      Bulk flour intake system

ü      Finished product Recipe Batch Handling

ü      A bulk out-loading system.

ü      Finished Product Packaging

ü      Purchases and Sales system

ü      Stock Control system

ü      Maintenance Log and reporting

ü      Production reporting

ü      Lab Test reporting

Fig1: Finished Products overview screen, which involves mixing, batching, weighing, packing and bulk flour

AUTOMATION SYSTEM DESIGN

The system was designed around a  Windows NT Ethernet network connecting via  a 100 Mbs Switch two of OMRON’s new CS1 PLC’s to 2 ADROIT 4.2 SCADA PCs with a Central Server  PC supporting the plant SQL SERVER 7.0  database, a site wide intranet for reporting and data entry with dial-up networking for remote support and reporting. Using Adroit’s  OPC client driver high speed communication between the PLCs and Adroit was facilitated via a Klinkmann Omron Ethernet OPC server.

All other computers on the site network have access to both

the Intranet and the ability to view live SCADA information via Adroit’s remote user interface option and the Ethernet network

The completed system is split into 2 areas.

  •  Intake and Mill section
  • Finished Products section

Each section is controlled by it’s own OMRON PLC and Adroit Agent Server.

The wheat intake system is able to bring in wheat from multiple rail or road trucks and has an electronic plug ID device sequence that keeps track of all data associated with the corresponding wheat being offloaded. Gross and tare masses, truck details and other important information is captured to the database through Adroit.

 

Fig2: Stock reporting web page on Intranet

Key System Benefits:

The Switched Ethernet network provides robust and high speed access between the SCADAs and the PLCs and between the SCADAs and the Server while facilitating access to both PLCs from the maintenance PC and access to the Intranet from any PC on the network

Information entry, such as recipe design, dispatch details, stock takes, maintenance reports and the results of laboratory tests are logged through to a central  SQL database from any PC on the network via custom designed web pages making up the site wide intranet

Production floor information obtained via the sensors connected to the PLCs is logged through Adroit 4.2 via it’s new DBAccess agent to a SQL database. In addition the advanced VB scripting features of Adroit 4.2 allowed easy fetching of recipe and production schedule information for SCADA display and PLC set up..

2 Adroit 1500 Tag Agent Server computers were used. One computer associated with the Mill section, and the other with the Finished Products section. Adroit 4.2 allows the SCADAs to be arranged in an Active Cluster, which gives increased reliability. If one of the SCADAs goes down, for any reason, the other SCADA will take over seamlessly and allow control of both sections without interrupting production or losing any data.

The new Adroit Marshalling agent was also a huge benefit in a project this big as it enables the grouping of all signals related to a piece of equipment           (running, tripped, start request etc) into one Marshalling agent, saving on tags and making fault finding, changing and documentation much easier.

Fig3: Wheat Intake, which can handle rail or road intakes, and transfer system.

System Commissioning

The initial discussions and design took place towards end of 2000. The finished products section was fully commissioned in a week and running smoothly by April 2001. The mill and wheat intake was commissioned in two weeks and running by July 2001.

Hard work, good ideas and easy to use software tools made this project another QUALITY ENGINEERING SOLUTION!