Product Description:

The EK1521-0000 is a fiber-optic EtherCAT coupler in the EK EtherCAT Couplers series from Beckhoff. As a fieldbus interface, it bridges copper segments and optical branches so that decentralized nodes remain synchronized across extensive production lines. The unit’s purpose in industrial automation is to transmit deterministic EtherCAT frames over glass fiber where electrical noise or long cable runs would otherwise degrade signal integrity.

The coupler employs a SC Duplex connector, giving two dedicated optical channels for full-duplex communication. It is specified for Multimode Glass Fiber, permitting cost-effective cables while still meeting bandwidth requirements. Inside the transceiver, a center wavelength of 1310 nm is used; this window balances attenuation and dispersion on multimode paths often found in plants. Receiver performance is framed by an input sensitivity of -31 dBm, meaning the photodiode can decode frames even when signal power has fallen to that level. On the transmit side, minimum launch power is -23.5 dBm, so the source delivers adequate energy to reach the remote node without saturating nearby receivers. The link design allows an optical power budget of 7.5 dBm, covering connector losses and fiber attenuation across typical installation distances.

When used as a network branch, the device takes the Junction role, forwarding incoming telegrams to multiple downstream strands without affecting cycle time. Firmware compatibility is defined by the DC support threshold of Rev. -0018 / FW 03, ensuring that distributed clocks synchronize correctly with earlier and later EtherCAT masters. The optical specification references 50/125 µm core-to-cladding geometry, so standard industrial multimode patch cords can be applied without mode-conditioning jumpers.