One cable automation combines communication and power

New connector technologies expand EtherCAT and EtherCAT P communication with additional power supply.

By Sree Potluri and Andy Garrido, Beckhoff Automation December 4, 2017

Connecting individual field devices, decentralized terminal boxes, and machine modules using one cable is accomplished by combining industrial Ethernet communication via EtherCAT with the power supply required by the connected components. For the 24 V field level, this was implemented using the EtherCAT P technology expansion connected via special M8 connectors. To provide additional power supply capabilities via one cable, new ENP and ECP connector types combine EtherCAT or EtherCAT P communication with additional power conductors in one cable. They are easy to use, are mechanically coded to prevent installation errors, and offer an IP67 protection rating.

The flexible single-cable automation design works for many applications. Different sections in a network can be connected by selecting appropriately designed combined power and Ethernet cables for devices and components according to power requirements. Unrestricted openness for mixed network topologies enables flexible transitions between: 

  • EtherCAT P communication with integrated power supply (one cable solution with M8 connector)
  • One cable solution using hybrid cables that combine an EtherCAT or EtherCAT P communication element with additional power conductors (one cable solution with the new ENP or ECP connectors)
  • A conventional two-cable solution with separate power supply (EtherCAT via M8/RJ45 connector or EtherCAT/EtherCAT P via ENP/ECP connector).

ECP and ENP connector types implement the combination of communication and power elements in different performance classes that range from 3 amps to 64 amps, in one compact design. The connector system is a completely new development and meets the full scope of OCA requirements regarding connected devices and modules, including drives, sensors/actuators, electrical cabinets, and entire machine modules. The following are benefits of this connector system including: 

  • Reducing the system to the essentials—namely the EtherCAT or EtherCAT P communication element and dc or ac power supply lines—creates cost-effective connection concepts
  • The system is easy to use due to the bayonet connections with mechanical and color coding
  • The power transmission integrated into EtherCAT P can eliminate the four wires normally required for 2 x 24 V
  • Allows the use of thinner, lower-cost cables and, alternatively, the supply of other voltages. 

EtherCAT P, 24 V, one cable

With EtherCAT P, EtherCAT technology has expanded to combine high-speed EtherCAT communication with a 24 V system and peripheral power supply (US or UP), in a standard Ethernet cable. Special M8 connectors were developed for EtherCAT P with mechanical encoding that eliminates possible confusion with connectors used for standard EtherCAT devices.

A specific machine’s design or plant installation is simplified using PC-based control software tools that help specify all individual EtherCAT P consumers and cable lengths to configure the highest performance and most cost-effective EtherCAT P network. 

Connector types: EtherCAT, EtherCAT P

If higher power or supplies are required in addition to the 24 V system and peripheral power supply via EtherCAT P, power can be supplied via corresponding hybrid cables with the ECP and ENP connector types for this purpose:

  • ECP (EtherCAT P + Power): This connector series combines a compact, trapezoidal EtherCAT P element (using the same pin allocation as the EtherCAT P encoded M8 connector) with additional power pins. In this way, the 24 V supply integrated into EtherCAT P is complemented with an additional power supply line.
  • ENP (EtherCAT/Ethernet + Power): These connectors combine a trapezoidal, central communication element with additional power pins in the same way as ECP. The trapezoidal element has an inverse design to prevent incorrect connections and provides data transmission via EtherCAT, standard Ethernet, or other Ethernet-based communication protocols.

Connector sizes from B12 to B36 are available with a varying number of power pins (two to six pins) so they can be adapted to the requirements of different network types and the power consumption for connected consumers. The complete and full-length 360-deg shielding of the central trapezoidal element continues the typical high-performance of EtherCAT. The compact design provides adequate space for the power pins, ensuring high current-carrying capacity and dielectric strength. The bayonet connection, and broad flange spectrum in the diverse housing variants-for rear panel, front panel, and square installation—provide further design flexibility. Connector versions for field assembly can save installation time. 

Broad range of applications

The ECP and ENP connector families, with the EtherCAT P-encoded M8 connector type, cover all applications from 24 V dc on the input/output (I/O) level to drive systems with 480 V ac and a maximum of 64 amps. The high-flexibility of the connection system is available in most application areas. Depending on specific needs, EtherCAT, EtherCAT P, or a mixture of both can be used. Typical engineering requirements for small and mid-sized systems are covered by EtherCAT P with up to 3 amps for US and UP in combination with M8 or ECP connectors. In contrast, the ENP connector series helps with larger installations involving longer transmission distances. The same also works for applications without EtherCAT P.

Expanding the one-cable designs with the growing diversity of the EtherCAT P, ECP, and ENP devices and components also expands the range of application options for users.

Sree Potluri, I/O application specialist; and Andy Garrido, I/O product marketing, Beckhoff Automation. Edited by Emily Guenther, associate content manager, Control Engineering, CFE Media,


Keywords: Power over Ethernet, EtherCAT, industrial Ethernet 

Key Concepts

  • Power and communications, single-cable design
  • The various applications for EtherCAT and power over one cable
  • Explaining EtherCAT and EtherCAT P communication with new connector types.

Consider this

How much time or space could an automation design save by using one cable power and EtherCAT in a standard Ethernet cable design?