At a global chocolate and cocoa manufacturer's Melbourne factory, Mobile Automation reconfigured the production and packing lines — mechanical, electrical, controls and safety, delivered inside a running food plant.
Four makers' machines brought into one line safety system
Each line carried third-party equipment that had to stop as a single system.
- Pattyn case erector, Mettler-Toledo metal detectors and checkweighers and a stretch wrapper tied into the line safety circuit
- Safety contactor fitted inside a metal detector to bring it fully into that circuit
- Combined E-stop and gate switching separated with an additional safety relay
- Every stop path proved in both directions — the line stops from the machine, and the machine stops from anywhere on the line
Making a stopped line explain itself
Operators needed to see what was holding a line down before calling maintenance.
- Safety overview and safety matrix built in Siemens WinCC
- Live state of every E-stop, isolator and plug shown for each line
Conveyor control, reject handling and data to the MES
The PLC work covered how the line runs day to day and what it reports back.
- Downstream-stop interlocking across the reconfigured lines
- Checkweigher reject handling with operator reset
- Bi-directional conveyor control, selectable from a local switch in manual or from WinCC in auto
- Analogue level-sensor control
- Reject data from the metal detectors and checkweighers passed to the plant MES over OPC UA
- Case-erector liner-timing fault resolved in the PLC program rather than by the mechanical rework the OEM expected
The results
- Production and packing lines reconfigured inside a running food plant
- Every stop path tested and documented, with a safety summary report and IO test records
- Live safety status visible to operators on the WinCC overview and matrix
- Data-cable mapping, as-built drawings and Standard Operating Procedures handed to the plant