Up to 1,024 sensors can be connected to 32 VPIs. The sensors require a connection to the VPI. The installation location for the VPI must be outside the potentially explosive atmosphere. The VPI is designed for DIN carrier rail installation and has eight intrinsically safe sensor terminals. Up to 32 VPIs can be circuited in parallel, depending on the quantity of sensors to be connected. * he following protocols are supported: T 1. FAFNIR Universal Device Protocol (UDP) 2. H-Protocol Features of the FAFNIR technology 8 intrinsically safe sensor terminals per VPI Connection of max. 32 VPIs in parallel possible = 256 sensor terminals One sensor terminal supports the connection of up to 4 different VISY sensors Intrinsically safe power supply Passive communication via RS485 Supply to VPI by commercially available power supply unit possible Two VPIs can be connected to one FAFNIR VPI-Supply (power supply unit) Easy DIN mounting rail installation, no additional enclosure required Maintenance-free Edition 07.2014 Technical changes reserved The VPI (VISY-Power Interface) provides a communications interface between the sensors and a higher-level system (master). For the sending of commands to the sensors, the VPI supports two protocols*. The response is assigned and forwarded to the individual