4 systems that work together with a station and are parameterised via a terminal, HMI.
Each PLC works independently with its own vacuum generator and its own central filter. The fill levels are checked. If it is detected that a separator requires refilling, the material requirements state of all separators belonging to this PLC will be frozen. The separators will then be filled in succession. The "freezing" of the material requirements ensures that the separators are filled according to the FiFo principle. Furthermore, this allows for large fluctuations in material consumption to be well compensated for. Once all separators have been filled once, the separators will once again be monitored to detect if material refills are needed.
If a vacuum generator fails, two lines can share a vacuum generator when operating with at least 2 PLCs. This does not mean that filling will take place smoothly just like when operating with both vacuum generators. However, it allows for operation of the "important" machines.