SyncTask

The SyncTask triggers the PROFINET task and thus the speed with which the PROFINET communication operates. By default the SyncTask is set to Standard (via Mapping). This means that the SyncTask is triggered via the mapping of the variables. If several tasks are linked with the PROFINET adapter, then the one with the higher priority than the SyncTask is always used.

Pay attention here to the task times of the SyncTask. These must correspond to the value x², i.e. 1 ms, 2 ms, 4 ms, 8 ms, 16 ms etc.
The PROFINET controller must then be set to the SyncTask or to the value x+1.

Example

SyncTask 4 ms, the PROFINET controller may then be set to the cycle time 4 ms, 8 ms, 16 ms etc. In this case cycle times of 1 ms or 2 ms may not be used. If the SyncTask is set via the PLC mapping, make sure that a breakpoint leads to the interruption of the task so that the PROFINET communication is no longer processed. In order to circumvent this case the Sync Task can be set to Special Sync Task; it is not necessary to link variables. It is recommended to use this setting, since it then runs independently of the PLC task and there is no synchronicity in the case of PROFINET RT for system-related reasons.

Pay attention to the system utilisation rate of your Embedded PCs. The shorter the PROFINET cycle time is, the higher the total system utilisation rate will be. A very high system utilisation rate can lead to an ADS connection no longer being triggered often enough and this connection may be interrupted. In order to enable trouble-free ADS communication the system utilisation rate should not exceed 70% (see System utilisation rate).