Product Description:

The EL5021 is a sine/cosine encoder interface terminal produced by Beckhoff within the EL EtherCAT Terminals series. The module fits directly on an EtherCAT I/O strand and translates analog encoder feedback into digital position data for motion controllers in industrial automation lines. It combines power distribution, signal acquisition, and network communication in a 12 mm housing. This arrangement lets a controller read encoder signals through the terminal without requiring a separate encoder card in the cabinet. It is intended for distributed automation architectures where feedback acquisition is handled close to the field wiring.

One differential sine/cosine channel is processed with an input sampling rate of 70 MHz, allowing the terminal to track encoder edges up to a maximum input frequency of 250 kHz. The internal counter has 24-bit resolution, while the transferred position word is fixed at 32 bits so higher-level controllers receive a consistent data width. Within each sine period, the terminal resolves phase information with 13-bit interpolation, and 8192 steps are available per period for fine motion tracking. The analog signals operate at a nominal level of 1 Vpp and are referenced to an average 2.5 V potential to ground, which helps maintain signal integrity on long cable runs. The terminal has one channel and typically draws 120 mA from the E-bus.

The encoder can be powered directly from the terminal by a supply of 5 V DC at up to 0.5 A, eliminating external power taps on compact machinery. With a minimum EtherCAT cycle time of 80 µs, position updates remain synchronized to fast control loops, and the terminal operates from a nominal system voltage of 24 V DC. Environmental protection is rated at IP20, making it suitable for installation in control cabinets where contact with live parts is limited. The housing format is suited to cabinet-mounted motion systems that need encoder acquisition at the I/O level.