RS Logix 5000 Projects Compare Differences

[Daelim]

Hi

While running the compare tool for two Projects, I am getting the attached difference in Program and Run. See attached.

The difference seems to be only graphically

Is it normal that the compare tool gives project difference even if there is slight difference in rung position?

As per my knowledge there is no difference in both the programs in terms of ladder logic execution, Please correct me if I am wrong.

Will appreciate Any insight and any info on this.

 

[DarrylR]

In the base project the branch level is extended. In the compare project the branch level is added. There really should be no difference except maybe scan time?

 

[drbitboy]

In the base project the branch level is extended. In the compare project the branch level is added. There really should be no difference except maybe scan time?

+1 agreed: no logical difference, the only functional difference would be the timing.

If OP double-clicks on the [0009] rung number on each, the "difference" will be apparent because there will be a few (one?) extra BST-BND pair.

Also note that the outer/bottom branch test [XIC L86WHRU XIO LRESET] could be appended as an extension of the inner branches. That said, this is a State Coil/Fault Coil pattern (see this link), with the inner branches composing the trigger condition, and the outer branch comprising the seal-in and break conditions, so leaving it as is makes it easier to understand.

 

[Operaghost]

Yes, position matters to the compare tool. But placing a new branch under an existing branch is different from extending an existing branch.

Your example on the left is considered one parallel branch with multiple levels, while the example on the right is a nested branch. Two branches, each with their own levels. Logically yes, they will function the same. However, nested branches are slower to scan and consume more memory. It is a small difference, but it is a difference.

Branches are actual instructions. Including the branch instructions, your example on the left contains 15 instructions. The example on the right contains 17 instructions. So of course, the report will identify that as a modified rung. It is more of a syntax check, not a logic check.

OG