CODESYS can be a fieldbus master for EtherCAT, PROFINET, EtherNet/IP, Modbus and other networks. With EtherCAT, a single frame travels down the line and every slave reads its outputs and writes its inputs as the frame passes through. This is called "processing on the fly." Watch one frame service the network in a single trip.
The master sends an EtherCAT frame down the chain. Each slave reads its output data and inserts its inputs as the frame passes, using hardware that processes the data in nanoseconds without stopping it. The frame returns to the master with all the data, every cycle. Press Run to follow the frame as it reads and writes data for all four slaves in one trip.
EtherCAT avoids a separate round trip to each device: one frame carries up to 1486 bytes of process data, enough to exchange this network's I/O in a single lap with microsecond precision. A network with more process data than that uses more than one frame per cycle. To add a slave, import its ESI description files into the device tree (Track 05), just like a GSDML for PROFINET.
⚡ EtherCAT uses on-the-fly processing, sub-millisecond cycles and distributed clocks for synchronization. It provides fast, deterministic exchange and uses ESI device files.
🌐 PROFINET & EtherNet/IP connect to devices in the Siemens and Rockwell ecosystems. They use GSDML/EDS files and cyclic provider-consumer exchange.
🔢 Modbus TCP/RTU is a common choice for meters, sensors and legacy equipment, and a fallback when other protocols are unavailable. The Schneider academy also covers it.
🚐 CANopen / J1939 connects CAN-based drives, vehicles and mobile machinery. You configure these networks in the same device tree as the other fieldbuses.
What makes EtherCAT exchange a whole network's I/O so much faster than polling each device?