Food Industry S5-S7 Upgrade

Customer: General Mills UK Ltd.

Segment: Food Industry.

Requirements of the customer:

• Customer did not have staff with Siemens S5 experience, the machine‘s software was complex and problematic.
• Task was to upgrade to S7 PLC as part of factory standard.
• Functionality to remain largely unchanged but had to be reprogrammed in Ladder as opposed to S5 STL language.
• Little downtime available to complete changeover.

The carousel mixer comprised of three stations linked with an indexing carousel to transport product around the machine. The machine produced a number of products and is capable of producing 1300Kg of dough an hour. The new control system allowed easy selection of recipes and the provision to make custom recipes as and when required.

Implementation

• Replaced S5 PLC with an S7-315 2DP linked via Profibus to an MP277 HMI
• New HMI interface much more user friendly.
• Maintenance staff familiar with the S7 system.
• Changeover carried out over a weekend and back in production for Monday morning.
• Program simulation carried out before system changeover using STEP 7 Professional software.

Benefits:

• Flexible user interface with alarm recording
• New S7 software structured and documented to facilitate ease of maintenance.
• S7 hardware used is now standard with newer lines and machines in the factory.
• Intuitive HMI screens mean that less training is required for new operators on the machine.