Introduction to ControlLogix Online Editing
ControlLogix Online Editing allows you to make changes on the fly. This means that you do not have to drop offline to make your changes, then download to your processor. When you download, your processor must go to program mode to accept the download. This means that if you were to download, your processor will stop executing logic.
Online editing allows you to make changes to a running project, but there are obvious dangers to be aware of. Your new logic will become active when you test your edits. Be sure your changes are correct, and understand how your changes will affect the process. You must also be aware of how the changes might affect the equipment in other operating modes, such as running a different type of product.
Changing an existing rung:
There are five steps for changing an existing rung:
- Start Rung Edits
- Make your changes
- Accept Edits
- Test Edits
- Assemble Edits
In Studio 5000, you also have a button to “Finalize Edits“. This will Accept, Test, and Assemble edits all at the same time. In this post, we will go through the steps individually.
Note: You cannot do an online edit if the keyswitch is locked into RUN mode. Also if you are in program mode, the last two steps are not required.
Here, we have a rung that is executing logic. We’ll walk through the five steps to change the XIC (the first instruction) to an XIO while we are online in Rem Run mode.
Step 1: Start Rung Edits
The easiest way to start rung edits is to double-click the rung number. You can also right-click the rung number to start pending rung edits. Another way is to highlight the rung number, and go to “Logic” on the menu bar | Online edits | Start Pending Rung Edits. CTRL+SHIFT+S is shortcut that you can use to start pending rung edits. Another way to start edits is to highlight the rung number, and click “Start Pending Rung Edits” in the Online toolbar. Most of these methods can be used with any of these steps, but here, we will just use the online editing toolbar. Be sure the rung is highlighted (click the rung number), and then click the icon for “Start Pending Rung Edits”.
Notice after you start pending rung edits, Studio 5000 creates a copy of the rung. The top rung is for us to work with. Look at the power rails. The Bottom rung is still executing in the processor.
Step 2: Make Changes
Now, we will make changes to the top rung. Notice the lower case i’s and r’s in the margin. The i’s mean the rung is marked for insertion, and the r’s mean that line will be replaced. They are lower case i’s and r’s. This means the changes are not in the processor yet. This is just an edit within Studio 5000 at this time.
I’m going to change the XIC to an XIO.
Step 3: Accept Edits
The next step is to Accept Edits. This will send the edits into our processor. The indicators in the margin will change to upper case, meaning the logic is now in the processor. Before accepting, be sure your keyswitch is not locked into RUN mode. You have two options in the online edit toolbar. One option is to Accept Rung Edits, and the other option is to Accept Program Edits. Here we only have one rung, so we will be sure the rung # is highlighted, and “Accept Rung Edits”.
Step 4: Test Edits
When you test your edits, the new rung will become active. Also be aware that if you are changing the output address, you might not have any logic writing to the old address. This means that you could abandon a tag in lit’s last state. When testing edits, it is possible to damage equipment and harm people. Be sure the rung is set up how you need it before testing edits!!
You will notice the TOP rung is running i the processor now if you look at your power rails. If you are not happy with the rung, you could “Untest” your edits, and then cancel edits.
Step 5: Assemble Edits
Now, we can eliminate the old rung in logic. Assemble your edits.
After you assemble edits, the old rung is gone.
Adding and Deleting a rung
To add a rung, just drag your new rung down into logic. Set up your logic on the new rung, then Accept, Test, and Assemble.
To delete a rung, just right click the rung number and choose “Delete”. The rung will be marked for deletion, then Accept, Test and Assemble.