Diagnosis
This function block is used to gather several information from the PLC and the program structure for diagnosis purpose.
The occurrence of “real-time” errors will be shown at output “RTErr”.
At the output “RT”, the runtime of the task can be measured from beginning up to execution of the diagnosis block in ms. To use as little memory as possible, this block should be the last block in the task.
„Real-time errors” always occur, when the execution of the program task altogether takes longer, than the period (cycle time) specified for one cycle.
Example without “real-time errors” (by activating or deactivating macros, different program runtimes can occur):
Example with „real-time errors“ (by activating or deactivating macros, different program runtimes can occur):
Example with „real-time errors“ during online communication
Signals
| Name | I/O | Type(s) | Function |
|---|---|---|---|
| RTErr | O | BIT | Real-time error |
| RT | O | WORD | Run time [ms] |