The EL1808 digital input terminal acquires the binary 24 V control signals from the process level and transmits them, in an electrically isolated form, to the higher-level automation unit. The EtherCAT Terminal contains eight channels, consisting of signal input and 24 V DC, whose signal state is indicated by LEDs. The power contacts are connected through. With the EL1808, the reference ground for all inputs is the 0 V power contact.

Special features:

• input specification type 1/3
• no bouncing due to mechanical switches thanks to 3 ms input filter
• tool-free connection by direct plug-in technique for solid wire conductors
• increased packing density with 16 connection points in the housing of a 12 mm terminal block

https://www.beckhoff.com/vi-vn/products/i-o/ethercat-terminals/el1xxx-digital-input/el1808.html