(Beginner question,step7) Data addressing

[dchartier]

Hello Kahorn;
Since I can't read you circuit, this is just a guess, but here goes:
When testing a program, sometimes you need to force a rung ON or OFF too see if the sequence operates correctly, under different conditions. Sometimes you include rungs in the original program that you find unuseful, and simply make them unsuable (with an "always off" bit) instead of removing.
Using an "always off" input will ensure that this particular branch will not become true during the test. This will be useful if you want to test the other branch exclusively.
Normally, though, I would expect the programmer to clean up the code and remove the "always on" and "always off" bits from the program...
Hope this helps,
Daniel Chartier
Edit:
Sorry Peter, just saw your post, Your trigger finger seems faster than mine.
D.C.

 

[kahorn03]

That surely did help.
The thing is that the programmer is on summer vacation, and the test were initially going to be performed before the end of his vacation.
In other words, I'm supposed to do the debugging...my biggest challenge ever.
However testdate will probably be delayed due to constructional problems, so at the time beeing miss Fortune is smiling to me.

Thanks again, to both of you!