Task configuration

Hello,
I am using Codesys to implement a simply application for PLC.
My question is about tasks configuration:
If I define a task (cyclic task) every 300 ms, what happens if task take more than 300 ms ? the next task start after 300 ms the previous task or it starts anyway ?
Do I have use watchdog to terminate it in 300 ms?

Thanks

The system will not have any time for other tasks, and yes it will immediate try to start again after it is finished as the flag is high.
yes you can use a watchdog but easier is to use a SFC as this is timed and it will go to next step when time is passed.
Codesys has own website and forum on 3s-software.com