Tags which are Used but never set/assigned.

[clementcbc 0]

Hi Guys, I'm using RSLogix 5000, V17. Is there a way to find all tags that are used (e.g. XIC, XIO etc) but never set? (e.g. it is used as in XIC, or XIO, or used as a Source etc, but never actually latch/energised/used as Destination). And also vice versa? I'm reusing some old code to build some new code. And every now and then i come across a bug where a Tag used in the code that probably has 0 or junk value. BTW, i'm not talking about unused Tags. Thanks!

[Ken Roach 194]

The cross reference function has what you need; it will show you what instructions use a tag, and it has a column labeled "Destructive" that has a "Y" or "N" to show if the instruction writes to the tag. But it won't find all the tags that meet that criterion; instead you need to specify the tags to cross-reference. You can do cross-references for array tags and get the results for all their sub-elements, but that's as close as you'll get to a search like the one you describe.