programing

What is the difference between the commands "Online" and "Online Now"?

Similar to when I tell my kids "Go to bed", and "Go to Bed, NOW!" ?

Just a guess.

It might help us if, perhaps, you told us what software you are using.

Or is that a secret?

Well Molson I am guessing that you are referring to RSLogix5 programming software for the Allen-Bradley PLC-5 processors. In the future you might want to post a few more specific details.

So, if we are referring to RSLogix5 then here you go:

Online
When you choose this option the RSLogix looks at the processor you are going online to and does a compare of the program in the PLC to the project file on your hard drive. If they match then the software will open the project file on your computer with the live data coming from the PLC.

If the files do not match, then you will most likely upload the processor file from the PLC and merge it with the documentation found in the project file on your computer. This will allow you to see your existing documentation merged with the program in the processor. If you do not wish to merge these files then you can instead create a new project file (on your PC) but you will only get default documentation, which ain't much.

Online Now
This option is similar to creating a new file as described above. It will not bother to check and compare the processor file to your files. Instead it just uploads the program into what amounts to a temporary file. You again will only receive default documentation.

So, if you do not care about the documentation, online now can be a quicker way of getting online with the PLC.

Hope that helps!

OG

OG-
Isn't "upload" an option?
I don't have RSLogix5 in front of me so I can't check.

If so how does "upload" differ from "online now"?
Or was there a re-phrasing in one of the later releases?

I'm not trying to say you're wrong, I am just curious

Allen Nelson said:

Similar to when I tell my kids "Go to bed", and "Go to Bed, NOW!" ?

Just a guess.

It might help us if, perhaps, you told us what software you are using.

Or is that a secret?

Click to expand...

Now... Where did I put that sledge hammer...


In answer to your second question, 93lt1: the difference between "upload" and "online now" should be similar to the difference between "online" and "online now."

Read the description Opera Ghost gave for "online now," and you'll see it. The key word is "temporary." "Online now" gets you access to the processor and its status bits so that you can do a quick check on how things are running. You're not expected to be doing any hard-core programming in this mode, so the uploaded file will be dumped when you go offline again. But, since I'm not a power-user of RSLogix5, I'm only guessing that this is the case.

That's my two cents... OFFLINE NOW!

AK

Sounds like it ought to be "ONLINE NEW" lolis

93lt1 ......

Isn't "upload" an option?

Click to expand...

Yes, the option for upload is there as well.

Use Online if...
You have the exact logic in the PLC and want to view the logic and the documentation

Use Online Now if...
You do not care about the documentation (as akreel mentioned) and you are just checking something quickly or making a small change.

Use Upload if...
You know you do not have the current logic in your PC and you want to view the existing logic with your documentation.

If you try to go Online and you do not have the current version then you have to upload first before going online.

If you Upload then after uploading you will be taken online.

So that's the deal!

OG

Operaghost said:

Use Online if...
You have the exact logic in the PLC and want to view the logic and the documentation

Click to expand...

I agree, somewhat.

Operaghost said:

Use Online Now if...
You do not care about the documentation (as akreel mentioned) and you are just checking something quickly or making a small change.

Click to expand...

I agree.

Operaghost said:

Use Upload if...
You know you do not have the current logic in your PC and you want to view the existing logic with your documentation.

Click to expand...

This is where I disagree. If you click upload, and even if you have the current logic/documentation in an offline file, RSLogix still creates a new file, and you would have to export/import your documentation. (Seeming the same as online now)

Your description of upload sounds more like RSLogix5000.