The EL5151 EtherCAT Terminal is an interface for the direct connection of one incremental encoder (24 V HTL). An additional 24 V digital input is available for storing or blocking the counter status. As an alternative, the EL5151 can be used as a up/down counter. The 24 V supply of the encoder can be provided directly via the terminal connection points.

Special features:

• save, lock, set counter
• integrated frequency and period measurement
• optionally usable as 24 V up/down counter
• microincrements
• synchronous reading of the position value via distributed clocks
• timestamp on the last-registered incremental edge

In addition, the EL5151 enables the measurement of a period or frequency with a resolution of 100 ns. With the optional interpolating microincrement functionality, the EL5151 can provide even more accurate axis positions for dynamic axes. It also supports synchronous reading of the encoder value together with other input data in the EtherCAT system via the high-precision EtherCAT distributed clocks (DC). A timestamp for the last-registered incremental edge is also available. The use of encoder profiles enables simple and fast linking of the process data for motion control applications.

https://www.beckhoff.com/vi-vn/products/i-o/ethercat-terminals/el5xxx-position-measurement/el5151.html