Sync Task
The PROFINET controller protocol must always be linked with a task. The protocol is also processed with the set task time. Theoretically the controller can also be jointly processed, for example, via a PLC or NC task. However, if a PLC project, for example, is stopped (e.g. by restart or debugging), this results in the PROFINET part also being stopped. In order to avoid such a side effect is it advisable to always create a free-running SyncTask.
Make sure that the task cycle is in a PROFINET cycle. For PROFINET the basic cycle is 31.25 μs. The basic cycle is obtained by multiplying this cycle by the SendClockFactor (SCF). The SendClockFactor is usually set to 32 for RTClass1. For the Beckhoff PROFINET controller this is also the minimum PN cycle for RTClass1. The smallest resulting cycle time is 1 ms. Further reductions take place using a ReductionRatioFactor. It always corresponds to a multiple of the minimum PN cycle. For RTClass1, the smallest cycle must always be doubled (permissible cycle times (for RTC1) with an SCF of 32 are 1, 2, 4, 8, ... 512 ms). In order to realize faster cycle times for RTClass3, the SCF must be reduced. This is presently at least 16 for a Beckhoff IRT controller (EL6632), which corresponds in turn to a basic cycle of 500 µs. When reducing the PROFINET cycle in this way, note that the time of the triggering task must also be adjusted accordingly.
 | Using EL663x When using the EtherCAT PROFINET gateway terminal, please note that the process data always arrive one cycle late in the PLC, since one cycle is required to transfer the process data from PROFINET to EtherCAT |