Plan a PLC retrofit from legacy P&IDs.
A 1990s control panel with a discontinued PLC reaches end of life. Operations wants like-for-like behaviour on modern hardware, the P&IDs have been redlined by hand for two decades, and the retrofit hinges on a clean I/O list that maps the legacy points without losing any.
How it works.
- 01Digitize the legacy P&ID setScan or pull the existing P&IDs into a workspace. Hand-marked redlines are common. High-resolution scans capture them. The extraction pulls instrument tags, signal classes, and equipment references from drawings older than the engineers reading them.
- 02Reconcile against the legacy I/O listMost retrofits start with an Excel I/O list that may or may not match the as-built drawings. Tagsight cross-references the extracted set against the legacy list and surfaces three buckets. Matched, missing-on-drawings, missing-on-list. The discrepancy report is the basis for site walks.
- 03Export to the target PLC platformOnce the I/O baseline is reconciled, export to TIA Portal XML, Rockwell L5X, or PLCCreator. The new PLC project starts with a complete tag table that mirrors the validated as-built scope.
What you get.
- Reconciled I/O list with legacy, drawing, list provenance per tag
- Discrepancy report, matched, missing on either side
- Target-platform export, TIA Portal, Rockwell, PLCCreator
- MOC-ready change record showing the retrofit scope
Common questions
What if the legacy drawings have hand-marked redlines that never made it back to the controlled drawing.
What is on the drawing comes through, redlines included. Reconciliation against the legacy I/O list catches the inverse case. A tag in operations that never made it onto a drawing. Site walks resolve the remaining differences.
Can the new PLC project start before the field walk is complete.
Yes. The 80 percent of tags that match cleanly become the seed PLC tag table on day one. The remaining 20 percent get added as the field walk closes them out.
Put it to work.
A 1990s control panel with a discontinued PLC reaches end of life. Operations wants like-for-like behaviour on modern hardware, the P&IDs have been redlined by hand for two decades, and the retrofit hinges on a clean I/O list that maps the legacy points without losing any.