The encyclopedia · Engineering & Operations · Technical decision · 2003–2007
EtherCAT beat fieldbus latency by processing Ethernet frames on the fly
Beckhoff's EtherCAT let each slave read and write a frame as it passed, cutting cycle times below 100µs; it became IEC 61158.
Beckhoff Automation · EtherCAT Technology Group
the move
Industrial networks in the early 2000s followed a stop-and-store model: every device received the whole packet, processed it and forwarded it, adding latency at each node — fatal for synchronized motion control. Beckhoff Automation designed EtherCAT (Ethernet for Control Automation Technology) around the opposite idea: processing on the fly.
A single EtherCAT frame travels through all devices in sequence; each slave reads the data addressed to it and inserts its own data into the frame as it passes, in hardware, with only propagation delay added. The EtherCAT Technology Group's spec reports effective data rates above 90% and cycle times below 100µs with jitter under 1µs, all over standard Ethernet cables.
Introduced in 2003 and standardized under IEC 61158 in 2007, EtherCAT was opened to the industry through the EtherCAT Technology Group, whose members include automation and measurement vendors — including DEWETRON, which built measurement modules that join existing EtherCAT networks as slaves.
why it works
- On-the-fly processing cut latency by removing per-node store-and-forward.
- Standard Ethernet cabling meant no exotic infrastructure investment.
- Hardware processing made cycle times predictable and independent of slave software.
- An open user group with IEC standardization gave buyers a safe long-term bet.
what transfers
When latency is the bottleneck, eliminate the per-node processing step rather than buying faster hardware; the design that removes a step wins the standard.
what came after
EtherCAT spread from motion control into measurement, robotics and test systems; the technology group's members integrate it into drives, I/O and data-acquisition products, and the protocol remains IEC-standardized, with power-over-cable extensions added while keeping backward compatibility.
references
spotted an error? The archive wants to know.