Industrial Ethernet Protocols

Factories are increasingly looking for open standards to support platform interoperability and avoid costly, proprietary solutions. Whether you need to support open or proprietary standards, Altera^® FPGAs enable the support of multiple industrial Ethernet solutions on a common hardware platform. The popular Ethernet protocols are listed below.

CC-Link

The CC-Link Partner Association (CLPA) manages the specifications of the open and global field network CC-Link, and promotes the worldwide adoption of CC-Link technology for deterministic network communications in industrial automation. To meet the changing demands for optimized control, openness, and reliable handling of large volumes of data on communication networks CLPA now presents an open 1-Gigabit Ethernet based integrated optical network concept (CC-Link IE). Recognizing these demands, CC-Link IE enables seamless data transmission from the information network layer to the field device layer. This is what the CLPA calls an integrated industrial network, and CC-Link IE implementation provides a cost reduction for the total system engineering task, from system start-up to maintenance.

EtherCAT

Ethernet for Control Automation Technology (EtherCAT) is the open, real-time high-performance Ethernet fieldbus protocol. EtherCAT supports any line, ring, or star topology; versatile and synchronized master/slave, slave/slave, and master/master communications with low jitter; minimum-effort implementation on devices equipped with CANopen; mapping of SERCOS servo drive profile to EtherCAT; and functional Safety-over-Ethernet.

EtherCAT is supported and promoted by the EtherCAT Technology Group (ETG), a global organization of OEMs, end users, and technology partners.

Ethernet Powerlink

Ethernet Powerlink is a deterministic, real-time Ethernet-based protocol. Powerlink can be described as a software solution for CANopen over Ethernet with real-time capabilities that rely on standard hardware and fully standard-compliant Ethernet frames. The Ethernet Powerlink Standards Group (EPSG) drives the specification and marketing of Powerlink.

Ethernet/IP

Managed by the Open Device Vendors Association (ODVA), Ethernet/IP for manufacturing automation not only provides the network tools to deploy standard Ethernet technology, but also enables Internet and enterprise connectivity for access to data 24/7 from anywhere. Ethernet/IP (and all CIP networks) implement the Common Industrial Protocol (CIP) at the Open System Interconnect (OSI) Session layer and above and adapt CIP to specific Ethernet/IP technology at the OSI Transport layer and below. CIP provides a media-independent communications platform for manufacturing automation applications such as control, motion, synchronization, and safety. ODVA’s CIP Safety, CIP Sync, and CIP Motion provide the network extensions for safety, synchronization, and motion into the wider enterprise network topology.

Modbus/TCP

Modbus is an open, royalty-free serial communications protocol for programmable logic controller (PLC) applications. Modbus/TCP is a Modbus/RTU message transmitted with a TCP/IP wrapper and sent over a network instead of serial lines. As with the serial Modbus architecture, Modbus/TCP is managed by Modbus/IDA, a group of independent users and suppliers of automation devices seeking to drive the adoption of this protocol.

PROFINET

PROFINET was developed by Siemens AG and is comparable to PROFIBUS. PROFINET adopts Industrial Ethernet standards for the automation environment that includes fieldbus-across- the-factory, office-to-factory, and equipment-to-equipment communications. PROFINET is designed to simultaneously handle standard TCP/IP and real-time transmissions. PROFINET uses PROFIBUS technology wherever possible to maintain system compatibility with legacy systems and can also interface any existing fieldbus to preserve existing investments in factory and networking equipment. PROFINET (and PROFIBUS) technology enhancements and promotions are directed by PROFIBUS International (PI). The PROFINET Trade Organization (PTO) addresses PROFINET for the North American region.

SERCOS III

SERCOS III upgrades the features of SERCOS I/II with a deterministic real-time, high-performance communications interface over Ethernet between motion controls, digital servo drives, and input/output (I/O) devices. SERCOS III uses the ring structure of SERCOS I/II, adds support for double ring signal flow to take advantage of Ethernet’s redundant data transfer, and uses a master/slave communication structure (the same with previous generations of SERCOS). Advantages of SERCOS III include compatibility with previous generations of SERCOS I and SERCOS II, integration of IP protocols, cross communication between slaves, synchronization of several motion controls, fault tolerance (double ring structure) in case of a break in the ring, hot plugging, safe communications drive safety functions, and half the minimum cycle time of previous SERCOS interfaces.

VARAN

The Versatile Automation Random Access Network (VARAN) bus standard is based on the IEEE 802.3 100TX standard Ethernet technology, the VARAN bus is implemented in hardware optimized to offload the control processor for machine automation. Founded in 2006, the independent VARAN Bus User Organization (VNO) supports the implementation of VARAN and continuing research, development, and application of new technologies.

IEEE 1588

IEEE 1588 is not a real-time Ethernet (RTE) communications protocol. This standard is an add-on to RTE or Ethernet. The IEEE 1588 Standard Precision Time Protocol (PTP) provides accurate real-time clock synchronization for distributed control nodes over an Ethernet network. IEEE 1588 is used with communications protocols like Ethernet/IP and PROFINET for real-time clock synchronization.

Industrial Ethernet Protocol Standards