Fieldbus is an industrial network system for real-time distributed control. It is a way to connect instruments in a manufacturing plant. It is a group of protocols that allows input devices such as Ethernet switches and sensors to communicate with output devices such as valves and drives without having to connect every single device back to a controller. Thus, providing efficient and effective means for connecting various devices to a single network and facilitating real-time control and monitoring. The Fieldbus protocols have been standardised as IEC61158.
There are multiple protocol options for Fieldbus systems and options can vary significantly depending on the application use. Below are some of the most common:
- EtherCAT
- Profinet
- AS-i
- Fountain Fieldbus
- Device Net
- Modbus
- ProfiBus
- InterBus
- ControlNet
- HART
- CAN
- Varan
- AS-I Interface
- DeviceNet
- Ethernet
- CIP
In this article we will be looking at EtherCat in particular.
EtherCAT or Ethernet for Control Automation Technology developed by Beckhoff Automation is used in industrial automation and real-time control systems. The protocol is standardized under IEC 61158 and is highly flexible and continues to develop at an exponential rate.
The logical topology of EtherCAT is bus, but the physical connection can be anything. EtherCAT device has multiple ports integrated so no additional switches or active infrastructure components are required and supports almost all existing network topologies: bus, tree, star, or daisy-chain. This not only reduces costs but avoids restrictions and limitations when designing a network. Also, the protocol has automatic link detection and can be set to automatically assign addresses, which eliminates the need for manual configuration.
The EtherCAT protocol is based on Ethernet technology and the IEEE 802 specification. It uses the same Ethernet frames and physical layer but with the following differences:
- EtherCAT is by and large the fastest Industrial Ethernet technology. It synchronises with nanosecond accuracy which reduces the wait times during the transitions between process steps.
- The EtherCAT architecture reduces the load on the CPU by 25 – 30% in comparison to other bus systems.
- No expensive interface cards or co-processors are necessary.
- EtherCAT protocol can be used in both centralised and distributed automation systems. Also, supports master-to-slave, master-to-master and slave-to-slave modes, as well as integration with other industrial protocols.
- The EtherCAT master needs just one command to poll to control several slave devices at once rather than a conventional Ethernet network which requires separate commands from master to slave devices.
- The protocol allows you to manage up to 65,535 devices in one network at high speed.
- EtherCAT meets the high demands of the Digitalization trend with its performance, flexibility, and openness and can used to connect to cloud services without having to reconfigure the master and slave devices.
- EtherCAT supports integration with the OPC UA Pub-Sub protocol, which can be used for machine-to-machine (M2M) communication and communication with cloud services
- No other technology can top EtherCAT’s bandwidth utilisation or the corresponding performance.
For more information, EtherCAT Technology Group (ETG) are hosting free of charge half-day (8.00 am – 1.00 pm) educational events. These are a great chance to learn about EtherCAT and the advantages to using this protocol including the opportunities to talk with EtherCAT experts face-to-face and see how EtherCAT can accelerate your application or project.
Discover the future of EtherCAT through gigabit performance and the integration of several communication technologies.
The EtherCAT Seminar series at the following dates and locations:
- Tuesday, February 7 | Melbourne
- Wednesday, February 8 | Adelaide
- Thursday, February 9 | Sydney
- Friday, February 10 | Brisbane
For more information on these sessions go to: www.ethercat.org/2023/australia
