For controls engineers: review the OEM's update before it hits your line
The machine builder's engineer did an online edit on site, then emailed "the final program" a week later. Your management-of-change process wants a review. Their release note is one line.
Rungview lets plant controls engineers compare the machine builder's new .ACD or .L5X with the version currently running, rung by rung. Changed, added and removed rungs are drawn side by side, and new, removed or retyped tags are listed. Check that interlocks, guard and safety permissives and timer presets are intact, then print the comparison to PDF for the change record.
A review checklist
- Every changed rung that touches a guard, e-stop, permissive or mode tag.
- Timer and counter presets that changed value.
- Removed rungs: where did that function go?
- New tags, especially ones that look like bypass or test bits.
- Changes inside AOIs, and any AOI that became source-protected.
How the comparison works
Open the running version, then Compare with… the new one. Routines are matched by program and name, and rungs are aligned so an inserted rung doesn't flag everything after it. Each difference shows rung A above rung B, drawn as ladder. Click into any routine to read the full context.
Keeping a record
Print the compare view to PDF and attach it to the change request. Keep both projects, and an L5X of each, in version control so the next review starts from a known baseline.
Review the next update properly
See every changed rung before it runs your line. Pro is $59 a year.
Get Rungview
.ACD and .L5X · read-only, never touches the PLC · files stay on your computer · cancel Pro any time.
FAQ
Does it compare safety tasks on GuardLogix?
Safety ladder routines are compared like any others. Rungview doesn't change safety signatures or connect to the controller.
What about Structured Text changes?
ST routines from L5X exports are readable side by side. Compare is strongest for ladder today.
Can I compare more than two versions?
Compare two at a time, for example running vs proposed.