Logix Designer/5000 Tag Database Cleanup

Hey everyone,

I'm working on a program that will be a smaller part of another contractor's plant control program for a hydro generating station. This program is in place at a few other stations and works great, but the contractor is building his program using the plant control program from a previous plant as a template.

In making our program, we basically just copied and pasted our routines from the program for the previous station into the contractor's and exported our tags from that program into the new one. In doing so, we ended up with a lot of clutter and a few instances of the same base tag having two aliases. I know this isn't an issue operationally, as the contractor is obviously only using his tags (and the old tags are pretty close to being the same anyways since he used the old program as a template), but the tag database is unnecessarily large and cluttered.

My question pretty much is if there's any way to do a search of all the tags that don't get used in the program? This would allow me to delete them and have a much cleaner and simpler tag database.

For reference, my Logix Designer is V24.00.00 (CPR 9 SR 7.1).

Thanks in advance.

Yes, In your Controller & Program Tags there is a drop down filter. Select Unused Tags and it will display all tags not used in the program.

Duh, that was easy. That must have been the one thing I didn't try to click in the filter/search options. Thanks again!

One thing to keep in mind is that if those tags are being used by an HMI they will still show as unused. Something to be careful with.

keshik said:

One thing to keep in mind is that if those tags are being used by an HMI they will still show as unused. Something to be careful with.

Click to expand...

Yeah, the HMI hasn't been configured yet, and the other contractor told us that it was ok to clear out the unused bits from the database. That being said, this is still really good to know.

Thanks!

Backup !!

You never know what might be lurking....

daba said:

Backup !!

You never know what might be lurking....

Click to expand...

I did this as well, saved the original (as REV0) before touching anything, then made a duplicate as a new separate file (as REV1). I had a scare recently where Logix froze my computer solid, requiring a restart, and I thought I hadn't saved recently (I had, thankfully ), so I've been extra diligent in saving and making backups.

Hey Mylespetro!

Check your "private messages folder"

Thanks

keshik said:

One thing to keep in mind is that if those tags are being used by an HMI they will still show as unused. Something to be careful with.

Click to expand...

I normally use dedicated HMI tags that are updated with the program's corresponding tag values in an interface subroutine.

"HMI_TagName", for example, so it's easy to recognize not to delete them.

JeremyM said:

I normally use dedicated HMI tags that are updated with the program's corresponding tag values in an interface subroutine.

"HMI_TagName", for example, so it's easy to recognize not to delete them.

Click to expand...

That's a great idea. The other contractor is handling the HMI, but we're planning to start doing it ourselves. Thanks for the tip!

FYI, if a HMI is using a tag and you try to delete it, you'll get an error message and the tag will stay. It doesn't even have to be using it *right now*, if you have a tag attached to a button on the HMI, even if you haven't pressed that button yet, the HMI still holds onto the tag and you won't be able to delete it.

At least, this works with a PanelView Plus, and works as long as the HMI is online and communicating with the PLC when you do it. Obviously, backup first!

ASF said:

FYI, if a HMI is using a tag and you try to delete it, you'll get an error message and the tag will stay. It doesn't even have to be using it *right now*, if you have a tag attached to a button on the HMI, even if you haven't pressed that button yet, the HMI still holds onto the tag and you won't be able to delete it.

At least, this works with a PanelView Plus, and works as long as the HMI is online and communicating with the PLC when you do it. Obviously, backup first!

Click to expand...

Always best to delete tags online, for that reason.

To be honest, I think this is the case with most hmi comms drivers, they cache their "connections" to PLC tags, so the tag database marks it as "connected".

Be aware that other equipment (e.g. SQL servers, Data Historians, etc.), may not hold their connections, and you may be able to delete tags that will be used in the future.

For that reason, I always advocate a tag-naming convention that includes the connection scope if it is external - (i prefer prefix), pretty much the same way that visual basic and other programming languages advocate naming data beginning with their type, e.g. int_PartCount.

So a PLC tag that is accessed by an HMI could be called hmi_StartButton, a tag accessed by SQL could be sql_ProductionRecord. It would be easy to spot these, and not delete them.

Another way to police this could be to create ALL tags as "External Access - None", and then to allow access to only HMI, SQL tags etc. In the database "Edit" view, you can sort by the "External Access" column to group all your "external" tags together.

daba said:

Always best to delete tags online, for that reason.

To be honest, I think this is the case with most hmi comms drivers, they cache their "connections" to PLC tags, so the tag database marks it as "connected".

Be aware that other equipment (e.g. SQL servers, Data Historians, etc.), may not hold their connections, and you may be able to delete tags that will be used in the future.

For that reason, I always advocate a tag-naming convention that includes the connection scope if it is external - (i prefer prefix), pretty much the same way that visual basic and other programming languages advocate naming data beginning with their type, e.g. int_PartCount.

So a PLC tag that is accessed by an HMI could be called hmi_StartButton, a tag accessed by SQL could be sql_ProductionRecord. It would be easy to spot these, and not delete them.

Another way to police this could be to create ALL tags as "External Access - None", and then to allow access to only HMI, SQL tags etc. In the database "Edit" view, you can sort by the "External Access" column to group all your "external" tags together.

Click to expand...

This is some great stuff to know. This is all offsite programming, so the HMI hasn't entered the picture yet. When we commission the system the other contractor will be setting that up.

He also does have the earlier version with all of the extra tags, just in case I did delete something that he planned on using but hadn't yet.