With a base unit and a contact expansion module PNOZ s7.1, the number of safety contacts can be expanded almost without limit. Up to ten contact expansion modules PNOZ s7.2 can be connected to a PNOZ s7.1. If you need more contacts, an additional PNOZ s7.1 can be added to the series. No need for wiring, it can be implemented in a single action via a connector.
At just 17.5 mm wide, the PNOZ s7.1 has three safety contacts, while the PNOZ s7.2 has four safety contacts plus one auxiliary contact. They can be combined with other PNOZsigma expansion units at any time. PNOZ s7.2 also guarantees that the supply voltage is "refreshed".
The following extract from the operating instructions for the PNOZ s7.2 describes how expansion modules are connected: besides a PNOZ s7.2, other PNOZsigma contact expansion modules such as PNOZ s7 or PNOZ s11 can also be used as terminator.