The EL5122 EtherCAT Terminal is an interface for the direct connection of two incremental encoders with A and B track. Encoders with single ended signals (TTL and Open Collector) can be connected. Due to internal pull-up resistors, no external circuitry is necessary for Open Collector evaluation. Per channel a 24 V digital input is available for storing, blocking and setting the counter status. It is also possible to set the counter to a predefined value or to lock the counter directly through the process data. The 5 V, 12 V or 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 5 V up/down counter
• synchronous reading of the position value via distributed clocks

In addition, the EL5122 enables the measurement of a period, frequency or velocity with a resolution of 10 ns. 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). 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/el5122.html