Revisit an old problem

[arkansascontrols]

My latest project is a large scale retrofit on an existing CLX system, that has been in place for a number of years and has had MANY undocumented field modifications done over the years.

The system has multiple racks on CNET, with around 2200 I/O system wide.

To complicate issues, there are some field mods that were 'Rigged' to avoid making Programming changes, ie. a VFD replaced by a reversing contactor that originally had multiple fwd/rev speeds has outputs paralled into contactors to make it work 'as is'.

So I'm tasked with documenting the current system, and then I have a series of Hardware/programming changes to make.

Looking at a single remote panel for an example I have 11 contiguous inputs that were never wired (spares) on one card. If I XREF these in the program it indeed comes up dry. However if I simply select "Unused" from the Show Drop down they aren't there. In fact selecting "Unused" from the Show Combo, would indicate that ALL real-world I/O tags are in use.

There are WAYYYYY too many points to have to XREF every single one to determine usage, so how in the hell can I quickly build a list of unused I/O points?

I've spent the last 18 months doing a similar project on another plant with SLC500 platform so my CLX is a bit rusty.

Thanks for any help guys.

 

[Ken Roach]

Points on a discrete I/O card aren't individual BOOL tags; they are sub-elements [x] of elements (I.Data and O.Data) of a Module datatype.

Therefore if you use even one I.Data[x] bit, the whole Module datatype tag is considered Used.

Would a Report that included a Cross-Reference do the trick ?

I think that when doing as-built documentation there's no substitute for perseverance.

 

[arkansascontrols]

Ken,

Yes a comprehensive cross-reference report would do the trick for me if it would enumerate which I/O points were in use. At this point I'd be willing to build a Spreadsheet, or even write a quick VB app to parse a flat file. Anything would be better than individually XREF'ing point by point.

This system has 13 Field Panels, each one with at least a 10 slot chassis in it. Some have more than one and they are all full or near full of discrete I/O modules. Some 16 point and some 32 point modules. I'll be elgible for retirement by the time I go through these individually.

Do you know of some XREF report that would simplify this process and provide the pertinent data set?