The EL1084 digital input terminal acquires the binary control signals from the process level and transmits them, in an electrically isolated form, to the higher-level automation unit. The EtherCAT Terminal has four channels that indicate their signal state via light emitting diodes.

Special features:

• ground switching
• no bouncing due to mechanical switches thanks to 3 ms input filter
• direct connection of four 2-wire sensors via additional 0 V connection points

https://www.beckhoff.com/vi-vn/products/i-o/ethercat-terminals/el1xxx-digital-input/el1084.html