Beckhoff products with XFC technology meet the requirements of applications that demand fast control, short response times, and deterministic control in the microsecond range. The technology includes EtherCAT as fieldbus communication, high-performance industrial PCs, I/O products such as IP20 terminals and IP67 box modules, and the flexible TwinCAT automation software.

XFC technology offers significant advantages through finer time resolutions for precision-critical processes. The optimized control architecture and integration of various forms of sub-technology enable response times of well under 100 microseconds. This allows highly dynamic and time-discrete processes to be implemented with excellent precision and reliability – even with standard components.

XFC technology comprises the following forms of sub-technology from various product areas: distributed clocks, timestamping/multi-timestamping, oversampling, fast inputs and outputs in the sub-microsecond range, and microincrements. These forms of sub-technology play a key role in ensuring the high performance and accuracy of the XFC systems.

Distributed clocks

Distributed clocks create a uniform time base across all bus devices, which is essential for time-critical processes and enables precise coordination of events across different components. This decouples the control actions from the control/bus cycle and makes them freely movable on the time axis. Distributed clocks optimize the performance and reliability of industrial applications by enabling time-deterministic acquisition and output of signals. With their uniform time base, distributed clocks provide the basis for all other XFC technology.

• distributed absolute system synchronization for unlimited CPUs, I/Os, and drive units
• internal time resolution: 10 ns
• distributed clocks accuracy: << 1 µs
• syncing with other time systems (external synchronization capabilities)

Timestamping

Timestamping/multi-timestamping offers the option of processing the uniform distributed clocks system time as a data type. This technology enables precise recording of timestamps for events in real time. Timestamping allows digital and analog events to be recorded and outputs to be set independently of the bus cycle. This allows multiple drive axes to be precisely synchronized with each other and with the system time, for instance. In contrast to timestamping, multi-timestamping allows several switch results to be processed per PLC cycle.

• Timestamping
  • high-precision time measurement for digital individual events per cycle: resolution 1 ns, internal sampling in the ns range
  • absolute distributed clocks time with 64-bit resolution, simple time handling of > 580 years
• Multi-timestamping
  • precision time measurement of up to 32 events per cycle: resolution 1 ns, internal sampling in the µs range
  • distributed clocks time with 32-bit resolution, sufficient for actions in a time range of ±4 seconds

Oversampling

Oversampling allows higher sampling rates to be implemented on the device side without changing the PLC cycle. This involves taking multiple samples per bus cycle at time-equidistant intervals, and one package of measurement data is transmitted. The high sampling frequencies allow signals to be captured with a higher time resolution and for higher-frequency signals to be recorded compared to the standard evaluation (1 measurement per bus/control cycle). The usual way to detect such signals would be to reduce the cycle time, but this is limited by practical constraints on the control system. For oversampling outputs, higher control frequencies can be implemented compared to the cycle, so that multiple control commands can be issued per bus/control cycle.

• support for analog I/O EtherCAT Terminals (as of 2024): signal conversion up to 100 kSps/10 µs
• support for digital I/O EtherCAT Terminals (as of 2024): up to 10 MSps/100 ns
• support for angle/displacement measurement (as of 2024): up to 100 ksps/10 µs

Fast reactions

Using I/O devices with a particularly low input and output delay of <1 µs, the bus signal can be converted directly into the physical output signal or vice versa. Together with the other XFC technologies, this enables the fastest possible signal processing within the Beckhoff standard components. In connection with the fast fieldbus communication via EtherCAT and the short control cycles of the high-performance Beckhoff Industrial PCs, extremely short response times can be achieved.

• control loops via the central controller of < 50 µs are possible
• deterministically synchronized conversion of the input and output signal leads to reduced process timing jitter
• process timing jitter is independent of communication and CPU jitter

Microincrements

When evaluating axis positions/encoders, microincrements offer time-based interpolation of additional increments between the real counted encoder increments, which increases the spatial resolution of the encoder count value. The current speed is measured internally and the microincrements are interpolated accordingly. This brings the encoder count value closer to the real axis position.

• interpolation resolution of 8 bits
• constant cyclic determination of the encoder count value by distributed clocks