Configurable small controller PNOZmulti 2 offers future-proof solution at NOM

(See Pilz at Machine Building North, 10 April 2025, on stand 62)

In the palletising area at NOM, relay-based muting controllers ensured that safety devices on 30 entry and exit points were muted while goods passed through. When these were discontinued, the dairy faced particular challenges: No replacement was offered, so they had to search for an innovative solution, which could imitate the functionality of the existing evaluation relays as well as the interaction with the light curtains, without intervening in the higher level controller.

External competence was called for, to provide support with planning and to accompany the process through to safety-related approval. Today, the flexible, safe small controller PNOZmulti 2 provides seamless muting, for the safe infeed and outfeed of goods.

The cold store at NOM operates 24/7; unplanned downtimes are a no-go. So two palletising systems were converted as the operation was running: the old muting controllers were dismantled and the light curtains replaced. The challenge: the higher level controller was involved in the muting.

Today, PNOZmulti 2 replicates the functionality of the existing relays, more precisely: all safety devices have dual-channel operation: If the plant controller signals the arrival of a pallet, PNOZmulti 2 performs the task of the previous relays: it mutes two control outputs, has this operation confirmed by the higher level standard controller and enables the goods to be transported. In addition, the automation system PSS 4000 is responsible for multiple stations. This was also installed by Pilz in just one weekend.

PNOZmulti 2 provided a powerful 1:1 replacement for the obsolete muting technology, with no need to intervene in the control level of the existing application. Further, the muting solution with PNOZmulti 2 is future-proof, configurable via software and open for all safety devices. Most importantly, the solution enabled an efficient refit, with practically no downtime

"The problem was that the existing application is not so easy to replicate, because the higher level controller is involved in the muting," said Michael Hronek, Automation Engineer and Head of Control Technology at NOM. "Pilz was therefore our knight in shining armour: from planning and installing the new components through to safety-related approval, everything worked perfectly, and it took the shortest possible time."