Run Timer

[roydm]

Hi All,
I have a number of pumps controlled by AB 1756L61 controller and I need to track the hours each one runs.
I configured a timer/counter to do this however if I download any configuration changes the elapsed time is ovewritten.
Is there some spot in the PLCs memory that I can use to retain values, and if so how do I access it?
I should also point out that I am not using a PC but have PanelView 2711 & +600 terminals.
I am using RSLogix 500 with Structured Text add-on.
Keep it simple please!
Thanks in Advance
Roy

 

[controlsdude]

Just make the changes online with the processor and you do not have to download.

Procedure
1 Have your changes done in an offline RSLogix5000 file.
2 open up another copy of RSLOgix5000 and get online with the old file.
3 copy and paste from offline into the online file. Compile or test your edits.

To access the tag value you just either right click on the tag that you want to view and monitor that tag. It will take you to the controller or program tag list.

When your done and save the processor will give you a choice to just save or upload the data table values. Upload the data table values too. If you dont upload the data table values, non of the timer preset, etc .. will be uploaded with the project file ACD.

 

[roydm]

Controlsdude,
Thanks for the response. I was able to follow your proceedure, it makes perfect sense. The problem is remembering to do it in the correct order.
I visit the site very rarely, most of the changes I do off line in the office and I have been downloading with the processor stopped.
I guess if I was making on-line changes it would not be an issue.
I thought there might be part of memory that doesn't get over-written by a download.
Regards
Roy

 

[Kiljoy]

Yes, it's the part you write on a stickey note next to the controller reminding you of the correct order ;P

 

[PLCMentor]

Roy,
I think this may be what you are looking for:

http://www.software.rockwell.com/support/download/detail.cfm?ID=3709

According to the description:
This tool allows you to download a project to Logix Controllers (v13 and higher) while maintaining existing on-line tag data.

From what I can understand, it grabs your data table info form the processor, saves it in a .csv file and, downloads your project and dumps the data from the .csv file down to the processor when you are done. Pretty much achieves preserving your data in the data registers.

So the catch is that I have never used this module, but it sounds cool.


Russell White, P.E.
Automation Technologies, Inc.

http://www.AutomationNC.com

Automation Help

http://www.PLCMentor.com

 

[controlsdude]

I will have to try that one. Sounds neat, too bad they give a disclaimer claiming they are not responsible. lol

btw, i have gotten into so much trouble downloading into processors. That I shy away from it as much as possible.
Doing online edits is my best way to stay out of trouble.

I will have to do a compare after to verify that it does what it does. Those disclaimers always get me.

I know in the siemens world that is only how it is done. You can only download. But you can just download individual files and not the whole project. There I still do a compare of online offline to make sure the changes are there. Thats the only sure way i have found on a siemens processor of whether the changes are there or not.

What about other manufacture's plcs?

 

[roydm]

PLCmentor, Controlsdude,
Thanks for your response.
The download from Rockwell seems to want to modify my RSLogix, I don't think I want to risk that. Oh well I guess I will just have to write the numbers down or do a screen print so I can put them back later.
I may be wrong but I am sure early Modicons had an area of memory that you could read/write but wasn't effected by a download.
As I only visit site about once a year, my configuration changes tend to be huge, too much to enter on-line.
Is it possible to up-load tag data only, i.e. suck it into the new configuration?
Thanks

Roy

 

[controlsdude]

Is it possible to up-load tag data only, i.e. suck it into the new configuration? I dont think so.

Right before you do your massive changes!
Like I said before, if you get online with the processor, do a save, then upload the data table, now you have the image of the processor from that point on.

Save this off as a backup point if you changes below go off the deep end.

Then copy and paste all your rung changes into this file online or offline. If you have other data table changes you can put these in too. If you have rack changes you do this at this point and do a download. Or just do the changes online, its up to you. Obviously rack, message changes require downloads.

 

[roydm]

Controlsdude,
Thanks for the advice. I am going to site later this week so I will try it out.
Regards
Roy

 

[PLCMentor]

Roy,
It's an add in for RSLogix. I really dont see there being an issue there.

controlsdude,
disclaimer? You probably need to check the terms on RSLogix. There is probably disclaimers on it letting you know it may or may not do what it is supposed to...

The legal world we live in.

The information included in this post should not be construed as advice or knowlege unless it works as you want it to. All claims made by this poster are for entertainment purposes only.

I guess I should have done a little more legal research.

Russell

Russell White, P.E.
Automation Technologies, Inc.

http://www.AutomationNC.com

Automation Help

http://www.PLCMentor.com

 

[roydm]

Hi Guys,
I was just at site and I tried to get my run timers working. I have a simple 6 minute timer. Every 6 minutes I take my variable e.g. (datatype REAL) and add 0.1 hours, this works fine.
I assumed if I entered a value into my tag P_XXX_RunTime in Off-line mode then downloaded the configuration it would take but for some reason the value I downloaded is zeroed out. If I go back off line the value I entered shows up in the tag, what am I missing?
RSLogix5000.
Thanks in advance
Roy

 

[PLCMentor]

Roy,
I suspect your logic elsewhere is contributing to the zeroing out. It would have been interesting to have just changed the value online while you were onsite. If you changed it and it changed right back then you can assume that other logic in your program is overwriting it. Possibly the addition you mentioned? If you want to attache your program or a pdf I will be happy to look at it.

Russell

Russell White, P.E.
Automation Technologies, Inc.

http://www.AutomationNC.com

Automation Help

http://www.PLCMentor.com

 

[roydm]

PLCMentor,
Here is is a sketch of my configuration.
It won't allow me to change the tag value On-Line but I thopught changing the tag value Off-Line should work??
As I said I can enter a value Off-Line but when I download it goes to zero.
When I go back Off-Line and my value shows again.
This is the only place I use the tag, other than Reading it with the HMI
I thought there would be a simple way of retaining the accumulated value.
I don't use RSLogix enough to become familiar with all it's quirks so any help will be most appreciated
Thanks
Roy

 

[PLCMentor]

I dont see anything there that would cause a problem, but as I mentioned, the problem is most likely somewhere else in your program.

Why cant you change it online? That may be related. When you say wont allow, what do you mean? As far as changing it offline, you can do that all day long. The program can have not affect on those registers because its not doing anything offline. You might try downloading it and leaving the processor in program mode. Go online then and see if your value is the same as offline.

You have it connected to an HMI. That may be affecting it. Most tags in the HMI's nowdays are bidirectional. They can read and write also depending on where the change is made. Should not be a problem but... If the program/run mode test above still overwrites your value then it may be the HMI overwriting. Try disconnecting and then doing the program/run test above.

By the way, does your value increment as you expect it to?

Russell

Russell White, P.E.
Automation Technologies, Inc.

http://www.AutomationNC.com

Automation Help

http://www.PLCMentor.com

 

[roydm]

PLCMentor,
Thanks for the prompt response.
I can't change the value On-Line as the tag is greyed out similar to a parameter in one of the function blocks when there is an external connection, perhaps because I am writing back to itself.
Yes the value accumulates by 0.1 every 6 minutes as expected if the pump status = 1.
I will try what you suggest next month when I go back.
I know it must be something silly, but for the life of me, I couldn't see the problem. I doubt it's the HMI since I just animated a piece of text rather than using one of the data entry keys but I will try that also.
I will keep you posted.
Regards
Roy

 

[PLCMentor]

Roy,
I am limited on how much I can play here since I have 'broken' my 5000 installation (dont ever do a Mcafee registry clean). I usually do the type logic you have in ladder and there is no problem changing the variable. Have you tried going to the controller tags table and seeing if you can modify the value there? I am assuming of course that you have the function block addon option with your 5000 software.

Russell

Russell White, P.E.
Automation Technologies, Inc.

http://www.AutomationNC.com

Automation Help

http://www.PLCMentor.com

 

[roydm]

PLCMentor,
Russell, I spoke about my problem with a colleague more familiar with Rockwell. He suggested that the tag value is being over-written by the ADD.Dest and I may be able to change that value before downloading changes.
It makes sense to me, how about you?
Regards
Roy