rsLogix500 rung descriptions problem

the rung descriptions have been automatically copying themselves on multiple rungs .. I have never seen it do that before. I like to enter lots of descriptions but it screws things up when it is reproduced on random(?) other rungs.

Also, something it always did which I like up to a point... If you enter a description for an element, it appears everywhere through the logic. I like that, but if you had a photocell and you put in the description that it was true when blocked, it puts the same description on the XIC as the XIO's I think it should not do that.

any suggestions? I never noticed the rung description thing until recently... maybe the RSLOgix 500 is corrupted or something?

The rung description attaches to one of two things, the rung number (which may get out of sync if you edit offline without the source open then upload into the source), or to the last coil on the rung. If that coil is used often in the project then the same comment will show up in multiple places.

As far as descriptions for an element I believe you have the option to attach a particular description selectively to the actual command type (XIC - XIO for example).

I name locations for the status (eg 'cylinder is forward') when they are TRUE ( 1 ). Then an XIO is easily interpreted as the negative of that status ('cylinder is not forward').

The rung description attaches to one of two things, the rung number (which may get out of sync if you edit offline without the source open then upload into the source), or to the last coil on the rung. If that coil is used often in the project then the same comment will show up in multiple places.

Click to expand...

I am not sure I understand exactly what you mean, but I believe I may have done exactly what you mean... I did not have access to anything but the program uploaded from the controller.

I tried to identify as many of the elements as I practically could, tried to edit on line... some things I could do , some I couldn't. I then put together a similar physical setup in the shop using everything the same except a ttl input card instead of a 115 vac input card and changing the I/O config to "any 16 input board" ( I got that here and it worked swell)

I then edited the program at the bench and tried it in the test setup. After that I downloaded it to the "real" controller and it seems to work fine.

I don't know exactly when the rung comments thing started... I think it was early on... but anyway, how can I correct the situation? I like lots of comments cause I can't remember anything

Plus, I think I will start using your naming convention... that makes sense thank you

Heres an example:

Note that "File/Rung" is selected.

The 'Page Titles' are nice also. If you have longer ladder files you can use 'Page Titles' to break it up into logical sections. Besides breaking up a printout, starting a new page at each 'Page Title' they also appear on the left as subsections below the ladder file name. You can even click on them to go to that specific section of the ladder file.

Rung Comment Attached to File:Rung
=======================
If editing the file will only be done from a single PC then attach the rung comment using the File/Rung option. This option allows every rung to have a unique comment.

This is also a good option if you store the file on a network and different PCs all access the one network file location.

Since the comment is tied to a specific location, if a different PC performed an edit, say adding a new rung, then your PC would not know about that change and the comments would be off by one rung. This is why there is an option in the software to adjust the run comment offset. If your PC makes the change then the comment is automatically adjusted.

Rung Comment Attached to Output
======================
If you have more than one PC that might be editing then this is usually the best option. With this option the comment is attached to the last output on the rung.

This option allows the comment to "find" the correct rung automatically. Even if the rung has moved to a different subroutine the comment will still "find" it. So if you make an edit on your PC, my PC will still show the correct comment attached to the correct rung.

This also means if you use the same output in more than one location then that same comment will appear in both locations. Usually this is ok as using the same output on more than one rung is considered bad form. However, in some cases it is necessary (OTL and OTU, CTU and RES). If you change the comment on the OTU then you are also changing it for the OTL. One comment attaches to every location.

Now, it does attach to the LAST output on the rung which means if you have a rung with a comment and you add a branch around the output and add a second output, your rung comment would disappear. Generally best to add additional comments ABOVE the existing output branch.

Address Comments
============
This attaches a comment to every location where that address appears regardless of the instruction type. You would see this comment in the logic, in the data file window, in a custom data monitor. Everywhere. This comment would display in addition to a rung comment.

Use the address comment to describe the address or the field device. DO NOT use this comment to describe what that address is doing in the logic since it will appear everywhere. Use your rung comment for that.

Instruction Comments
==============
This attaches to the combination of the address and the instruction type. This would allow your XIC and XIO of the address I:3/5 to have different descriptions. However, if you use the same address and the same instruction combination in another portion of your logic you will see the same comment. If you want different descriptions, use a rung comment.

The instruction comment and address comment both appear in the same space above the rung. So while it is possible for an item to have an address AND an instruction comment, the instruction comment trumps the address comment and would be the one that is actually displayed.

Page Titles
=======
Horribly misunderstood and underused. Page Titles are primarily used as a search tool. Page Titles identify sections of your logic and can be displayed like a Table of Contents. When you display this Table of Contents you can click and jump directly to that section. One of the features I dearly miss in the newer Logix 5000 systems.

When you select to attach your rung comment to the File:Rung or to the Last Output, this also affects the Page Title. Same rules mentioned above apply for Page Titles.

OG

Good Lord... what a wealth of info. every bit of it very useful and well explained

A little of it I knew, but I will be attempting to learn and incorporate all of this from now on

thank you all very much

My preference is to attach comments to the output address. This can be problematic when you have a bunch of rungs that operate on that same address as the last instruction. In those cases, I add the venerable "comment placeholder" dummy bit so I don't have to switch to the file:rung method. Note that you can have both, and if you delete a rung comment, and then another one magically appears, that is likely the case.

You can also "browse" all of your rung comments in the project tree in the lower left area and it will show you not only all your comments and to what they are attached, but also old abandoned rung comments that end up left behind after eons of editing. This can happen if, for example, you attach a rung comment to N7:0, then later on you decide to use N17:27 for that function, and copy or rewrite the rung comment without deleting the old one. N7:0 may no longer be used anywhere in the program, but the rung comment for it will still exist in your project file.

This is just my preference, after dealing with rung comments getting moved all around inadvertently when attached to a file:rung location. And some old versions of RSLogix500 waffled on how they handled them. It is not necessarily the best way.

This can happen if, for example, you attach a rung comment to N7:0, then later on you decide to use N17:27 for that function, and copy or rewrite the rung comment without deleting the old one. N7:0 may no longer be used anywhere in the program, but the rung comment for it will still exist in your project file.

Click to expand...

Unused rung comments and address descriptions can be deleted from the RSLogix500 database by selecting "Tools, Database, Rebuild DB, YES (to delete these unattached records)".

OperaGhost said:

...
Page Titles
=======
Horribly misunderstood and underused. Page Titles are primarily used as a search tool. Page Titles identify sections of your logic and can be displayed like a Table of Contents. When you display this Table of Contents you can click and jump directly to that section...

Click to expand...

Just to add. This feature is not enabled by default. To enable it...

Go to Tools --> Options --> System Preferences and check Integrate Advanced Diagnostics in Project Tree.

Don't forget SYMBOL names. They are quite useful as well for quick editing and can also assist with the descripton of different instructions for the same address. Symbols are asigned to the address only and not the instruction. You can assign a generic symbol name to an address, such as 'PC_CUT_ARM_POS' (PHOTOCELL_CUTTING_ARM_POSITION). Then use the instruction description for an XIC of the address and call it 'AT HOME POSITION' and XIO 'NOT AT HOME POSITION', or similar. As you already know what the instruction is evaluating from the symbol name, this cuts down on the detail required in the instruction's description.

George