Opening two copies of RSLogix 5000 program

Today I was troubleshooting a machine that is acting oddly. I wanted to compare the current plc program that I had open and was on-line with to a previous version

So I opened another instance of RSLogix 5000 and then opened a year old version of the plc program. I did not go on line with that one.

Well that messed up my view of the on-line RSLogix5000 session.

Okay, I'll close both instances of RSLogix 5000, that will make it right.

Re-opened my current version of the PLC program and it looked fine, I went on-line and I had a rung that I'd been viewing that had all branches, no instructions and the e along the rung.

Meanwhile the machine is merrily running along. I went and got help / a witness. My coworker plugged in his laptop, went online, the program looks great. He saves a copy to his laptop.

I decide to reboot the pc that I run RSLogix5000 on as it must be corrupt some way. We load the program file I was using and when we went online it showed that rung missing most of the instructions now.

Finally, my coworker took the file he saved on his computer after going online to correlate with controller, opened it up on my computer and all is good.

Is what I was attempting to do not allowed? The online version is named something like project_20170719a.ach and the old version project_20160413a.ach so they are different disk images.

Thanks

Well, sometime I got 5 or 6 instances of 5000 open, plus someone else going online to the same PLC I'm online with. Never really had any issues.

and the e along the rung.

Click to expand...

if everything else is equal (it seldom is) then having LITTLE letters (lower case letters) is supposed to mean that the "change shown on your computer screen is NOT yet present in your PLC's logic" ...

so ...

that might help explain how the machine was still running OK - regardless of what you saw on the computer screen ...

harryting said:

Well, sometime I got 5 or 6 instances of 5000 open, plus someone else going online to the same PLC I'm online with. Never really had any issues.

Click to expand...

Usually I have 3 instances of 5000 open for three separate processors.

I have done exactly what was described -- opening archived versions simultaneous with the current -- without issue.

That said, I am quite sure I have also experienced the spurious new rung thing, sometimes with unknown instructions. I figured I inadvertently hit the insert key or some other PC anomaly created the rung.

Next time it happens, I plan to try the startup reset (ctrl+shift click) for RS-Logix 5000 to see if that removes the bad rung. I also recall having difficulty deleting it.

Most likely this occurred with 20.03; though it could have been with older versions also open.

Plain facts....

You cannot open the same project more than once on one PC. A rudimentary file-locking system prevents this.... but read on...

You can open a copy of a project, in another folder, even with the same name, on one PC, but that is not the same project as above. The file-locking only works to the files folder level. You can be online with both.

You can have the same project open on multiple PCs, so long as they have their own local copies of the .ACD file, i.e. not network served-up.

Multiple PCs can be "online" to the same controller, but that does not mean their respective .ACD files have the sane filename.

I don't know of any limit to the number of "on-liners" to a single controller, other than that imposed by connection count through the communication path.

You can have as many projects open as you wish, in separate instances of the programming software, depending on your PC capabilities (mainly memory). All of your open projects can go "on-line" to their respective PLCs, depending on connection count.

Not sure what the actual cause is, but I have always found it happens more frequently when multiple people are online with the same PLC. The easiest way to resolve the issue that I have found is to close your corrupt file, save a copy of someone elses file, and go online with that. If you had the "master" copy (with all the most recent descriptors), then you are forced to actually fix that rung. If someone else has a copy, it is easiest just to rewrite that rung in your master copy, based off their screen. I remember it being somewhat of a pain in the *** to get rid of the corrupt rung as well. If I am remembering correctly you need cancel edits, maybe even untest edits, before it will let you delete it.

I have been using v28 for the past several months and have never once had this issue since I upgraded.

Just to add a little more info on the topic of more than one user online to the same controller...

25961 - Guidelines for multiple RSLogix 5000 users online with the same controller at the same time
Access Level: TechConnect

wes.s,

What happened here is undoubtedly corruption of one project file's offline image by effectively opening another instance of the same program, as daba has explained. The temporary *.sem and *.wrk files that are created in a project's folder location when you open it cannot be created for the same project twice. So attempting to effectively open the same project twice, from within the same folder location, will yield undesirable results.

Simply saving the same project using another name, such as a date stamp, makes the project files distinguishable to you, but to the software they will still correlate as being the same.

If the current project had not been edited sufficient enough to update the change log since the year old project was last saved, then they are effectively still the same project file.

Because only the offline image was corrupted in the project that happened to be online, the online image was not affected. You initially saw pending edits denoted by the lowercase "e". As Ron has pointed out, this indicates pending edits in the software only and not in the processor i.e. in the offline image only.

When you rebooted and reopened the affected project file once more, you then found the same rung was further corrupted. Again, this was only for the offline image in the project file. So at no point was the online image affected that was running in the processor when this project was online to it.

Uploading from the processor, using the corrupted project file, is the software's method of recorrelating or synchronising the online image with the offline image once more.

Now, if you come back telling me that the current project file was extensively edited from the year old copy, well then, I'll just have to make something entirely different up!

Regards,
George