Hey guys,
Apprentice, second year, plastics plant. The granulator line runs on a CompactLogix 1769 L33ER, Studio 5000 V32 I think. My supervisor let me add a Structured Text routine that looks up a product code in a DINT array of 50 entries and gives back the position.
Downloaded it Friday afternoon and within about ten seconds the OK light went red, Type 06 Code 01, task watchdog expired. Cleared it, back to run, faulted again exactly the same way.
```
i := 0;
WHILE Codes[i] Product DO
i := i + 1;
IF i >= 50 THEN
i := 0;
END_IF;
END_WHILE;
Position := i;
```
I raised the continuous task watchdog from 500ms to 2000ms and that made no difference, then I ran it in Emulate at home over the weekend and got the same fault there.
It's only 50 entries so it should take nothing. Is ST just too slow for this on a 1769?
What happens when Product isn't in the array? Read the loop again with that case in mind, and tell me what the IF at the bottom is for. Also, continuous or periodic task?