Editing AOI's in RS LOGIX 5000

Hi everybody I am a beginner in the PLC world at least when it comes to making changes and edits. I want to edit some timer values inside an AOI and was wondering if I could get some tips or things to consider from some of you more experienced controls guys. I guess some specific questions I have would be, if I change a timer preset value will it make that change to every AOI in the program (this is an AOI used in multiple routines). I only want to change it in one of the routines at least for now so I can verify smooth operation. As I understand you can only edit AOI's offline? So go offline type in new value into the MOV instruction that sends it to the timer preset then download it? Thanks!

dalcoleman said:

Hi everybody I am a beginner in the PLC world at least when it comes to making changes and edits. I want to edit some timer values inside an AOI and was wondering if I could get some tips or things to consider from some of you more experienced controls guys. I guess some specific questions I have would be, if I change a timer preset value will it make that change to every AOI in the program (this is an AOI used in multiple routines). I only want to change it in one of the routines at least for now so I can verify smooth operation. As I understand you can only edit AOI's offline? So go offline type in new value into the MOV instruction that sends it to the timer preset then download it? Thanks!

Click to expand...

-If you change a timer preset value, it will make the change to every AOI in the program, if the timer .pre is a Local tag inside the AOI.
-Correct, you can only edit AOI's offline
-I recommend saving a copy of the original AOI before you make any offline edits
-Another thing to consider, is making the timer .pre into a Input parameter of the AOI, then the value can be modified as needed every time you use the AOI.

The timer is a local tag but this particular instance we have a parameter tag sourced to a MOV instruction that moves it to the timer. So I guess one of the reasons that's a common way to program is by doing it that way it will allow me to change its value in this AOI only? Thanks!

Correct.
If there is an input tag that is moved into the timer.pre tag then you can change it in one instruction and it will not change the others.

dalcoleman said:

The timer is a local tag but this particular instance we have a parameter tag sourced to a MOV instruction that moves it to the timer. So I guess one of the reasons that's a common way to program is by doing it that way it will allow me to change its value in this AOI only? Thanks!

Click to expand...

Not sure I understand 100%. It sounds like the MOV is outside the AOI. In that case, change the value in the MOV and it will only affect this instance of the AOI.

A_G said:

-If you change a timer preset value, it will make the change to every AOI in the program, if the timer .pre is a Local tag inside the AOI.

Click to expand...

This is not correct.

Let's back up a little bit.

You can only edit the *logic* of an AOI offline. That is, if you need to add a new instruction, change the order of some instructions, add a rung, delete a rung, delete an instruction - it can only be done offline.

You can edit the *tag values* of an AOI online. That is, you can change a timer preset, change the value of a DINT or a REAL that's used within the AOI, toggle a bit on or off, etc etc. All can be done online.

A good way of working it it is to imagine the same change taking place *outside* an AOI. If your change means you have to edit the rung (double click on it, make your changes, and then assemble the edits), then you can't do it to an AOI online. If your change can be done without having to edit the rung, just by clicking on a value and changing it, or clicking on a bit and toggling it, then you can do it to an AOI online.

Next. Every time you create an AOI, it creates a unique data structure for that AOI. Let's say I have a motor AOI, and I create three of them, called Motor_1, Motor_2 and Motor_3. Each of these data structures are fully independent. If there's an input parameter called, say, "StartupTime", then I have three completely separate tags: Motor_1.StartupTime, Motor_2.StartupTime and Motor_3.StartupTime. Changing any one of these tags does NOT affect the other two. So, if you change a timer preset inside one AOI, it will NOT affect the timer preset of the other two.

If you change the timer preset in the AOI definition (as opposed to e.g. within the Motor_2 instance of the AOI), then all future AOI's will be created with that new preset value. They can of course be manually changed to whatever value you want, as previously described. But regardless, all timer presets in your existing AOI's will remain unchanged.

However!

You can enter the AOI properties, and change the default value of all of your parameters and local tags. If you were to change the default value of a timer preset in the AOI definition, then you get asked "do you want to apply this new default value to all existing AOI's or leave them as they are?". If you select to apply to all, then Motor_1.StartupTime, Motor_2.StartupTime and Motor_3.StartupTime will all have their values changed to that updated value. This can only be done offline.

Now back to your specific scenario, you have a MOV instruction which sets your timer preset. If that MOV instruction moves a constant value (e.g. 1000, 2000, 12345), then to change it you would need to edit the rung, which would mean doing it offline and downloading it. Obviously, this will affect all existing instances of that AOI.

If the MOV instruction moves a tag value (e.g. StartupTime, which may have a value of 1000, 2000, 12345), then you can simply change the value of that tag online, and it will not affect any of the existing AOI's.

Personal opinion: there are very few times you should be MOVing a constant value within an AOI. The whole purpose of an AOI is that it's re-usable, and each use will likely need different parameters. You should always, as A_G mentioned, have your MOV instruction be moving an input parameter into your timer preset, so for each AOI you can change timer presets by changing input parameters with no need to even look inside the AOI.

Hope some of that waffle is helpful!

One technique that I use to avoid having to do a MOV of an Input parameter into a timer preset is to make that Input parameter tag an ALIAS of the local Timer tag's .PRE.

Now the .PRE is exposed outside of the AOI, and I'm using less memory and fewer instructions (not that either matter much anymore in modern processors).

Similarly, I alias HMI command but into a single word, which I then DID with its last-scan value into itself to reset any HMI but after one scan. Saves on lots of Unmatched and downloads to fix things when I forget.

Aliasing is a great way to access non-basic data types without needing to use InOut parameters.

Anybody know if we are able to make edits to an AOI that does not have an instance while online with the controller?

Not as far as I know, although I have not had need to edit AOIs in the newest revisions.

I've been hoping for such a feature for some time; you can work around the lack to some extent but it's a hassle.

A few options:
1. export the AOI and make changes needed Then import AOI with new name. This can be done while online.

2. export the AOI and make changes needed. Then Right click on the AOI if the delete selection is ghosted out then there are tags associated with the AOI. Then delete all tags in the AOI. Delete all tags in the project associated with the AOI. Once all tags are deleted then the delete selection should be available. Make your changes an import AOI back into the project. Then you can use the same name of the original AOI.

3. You want to try to right click on the AOI and use the rename feature. Give the unused AOI a different name. Then you can use the export/import feature to make changes and reuse original name.