With the function blocks in the TwinCAT PLC Motion Control XFC library, the time stamps of EtherCAT Terminals can be acquired with high precision and converted into the corresponding axis positions. The EL1252 digital input terminal records fast binary control signals with a resolution of 1 nanosecond (ns). This technology permits signals to be traced exactly over time and synchronised with EtherCAT distributed clocks across the system. This allows, for example, the storage of the current position (latches) at arbitrary places in the EtherCAT system. An appropriate touch probe block according to the PLCopen standard is available in the library. Up to now, high precision latching has only been possible directly on the drive, often with only very few inputs. This can now take place locally at any point using the XFC library and the appropriate time stamp-based EtherCAT Terminals. This saves wiring and makes virtually any number of latch inputs possible.

On the other hand, it is very simple to convert axis positions into highly precise times. This allows high precision cam controllers to be realised. The time stamp-based digital outputs of the EL2252 or EL2262 EtherCAT Terminals can similarly be arranged at any point in the EtherCAT fieldbus system. A TwinCAT PLC function block according to the PLCopen standard is similarly available for cam controllers.

The prerequisite for the maximum attainable accuracy is the automatic dead time compensation of axes, which is available for EtherCAT and SERCOS drives from TwinCAT 2.11 onward. An exact correlation between time and position can only be achieved with dead time compensation.