PFC200 and CC100 both have 1 processor, so tasks like runtime (high priority) or nodered (low priority) have to be call one by one. If you set runtime tasks with high priority and also low timing the system scheduler will prioritize runtime, so nodered can be even choked.
What can you do?
Use htop command with console:
Download PuTTY ( Download PuTTY - a free SSH and telnet client for Windows) it is a SSH client, so we can connect do PLC console via SSH
How to change htop configuration to see task names:
and check if Load average is near 1-2, if not, change codesys tasks time or change 751-9412 CC100 (2 threaded processor) or PFC300 (4 threads)
Task priority advice:
