The EL1004 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 has four channels that indicate their signal state via light emitting diodes.

Special features:

• input specification type 1/3
• no bouncing due to mechanical switches thanks to 3 ms input filter
• direct connection of four 2-wire sensors via additional +24 V connection points

https://www.beckhoff.com/vi-vn/products/i-o/ethercat-terminals/el1xxx-digital-input/el1004.html