The Background.

Our client had reliability issues with an out of date, obsolete control system the client, and were often faced with machine failure with no indication as to why this had occurred.

This resulted in long periods of unnecessary downtime whilst their engineers worked to debug the code and find the reason behind the failure.

As the existing process-control system based on a Siemens S5-135U became difficult to support, the decision was made to upgrade to a state-of-the-art system.

The Client: Milk Link

Our client is part of a global dairy supplier with 9 large production facilities in the UK.

The Solution.

Following consultation with the plant engineers iTech put forward a solution based on a Siemens S7-400. The PLC program was converted from S5 to S7 and then examined to extract all the possible causes of alarms and errors which could affect the machine.

Set point / configuration values relating to the machine setup were also extracted from the original code. All these configured alarms and values were then configured on a Siemens Touch Panel TP277B HMI, allowing the process operators to visualise what was happening on the machine for the first time.

A simulation program was produced for the machine so that the process operators and plant engineers could run / test the program to ensure correct functionality. The changeover from the old system to the new control system was made during a scheduled machine outage with no production losses during a busy period. When required, the machine started up and ran as normal with no problems.

Services supplied include:

  • Detailed engineering and design
  • PLC & HMI software
  • PLC & HMI hardware
  • Installation Mechanical / Electrical
  • Re-engineering control panels
  • FAT, SAT and commissioning

The Benefits.

The client now has a system which offers a comprehensive range of control features, enabling the process team to easily identify faults and modify production parameters.

The plant control was changed with no disruption to the production during a busy schedule.