What is a tie-in I/O list and when do I need one?

A tie-in I/O list is the engineering deliverable that names the new and modified instrument tags added to a facility when a piece of equipment is connected to an existing system. It is needed on every brownfield tie-in so the PLC engineering team can size the new I/O cards, the panel shop can wire the new loops, and operations can verify the existing controls are not disturbed.

How does Tagsight scope the new tie-in equipment on an existing P&ID?

On the v3 review canvas, drag a rectangle around the new equipment area on each affected drawing. Tagsight re-extracts just that region using the same vision stack the baseline pass used, and merges the new tag rows into the project. Every region drag is logged in the project audit drawer and is reversible.

What is in the Excel Change Report for a tie-in revision?

A Summary sheet with Added / Removed / Modified counts, plus three colour-coded tabs: Added Instruments in green, Removed Instruments in red, Modified Instruments in yellow. Each row carries Tag Number, Instrument Type, Signal Class, Description, Location, and source-page reference.

Does Tagsight support TIA Portal, Studio 5000, and PLCCreator for the merged export?

Yes. The merged I/O list exports as a Siemens TIA Portal XML GlobalDB block sized for S7-1200 or S7-1500, as a Rockwell Studio 5000 L5X for ControlLogix 5380 or 5580, or as a PLCCreator Device IO List CSV that covers Honeywell Experion, Schneider EcoStruxure, Yokogawa CENTUM, Emerson DeltaV, Foxboro Evo, and ABB 800xA.

How is the existing baseline re-used across multiple tie-ins on the same facility?

Once a facility's P&IDs are extracted into a workspace, every subsequent tie-in runs as a revision on the same project. The baseline extraction is cached. The new tie-in tags merge into the baseline, and the comparison runs against the most recent revision so each tie-in only handles the delta.

Is the region re-analyze step free, and what are the limits?

Yes, region re-analyze is free to the user. Each project has a 25-region lifetime quota and a 5-per-minute rate limit. A 60-second idempotency window deduplicates accidental same-bbox reclicks. The limits are operational guardrails; a typical brownfield tie-in uses 1 to 3 re-analyses per project.

Tie-in I/O lists, extracted from the existing P&ID set.

Upload the current P&IDs to baseline the facility. Drag the new equipment region on the canvas to extract the tie-in scope. Compare, merge, and export an updated tag table to TIA Portal, Studio 5000, or PLCCreator.

OutputExcel Change Report + merged tag tableStandardISA 5.1 + corpusWorkflowRegion re-analyze + revision diff

Start a workspace See the worked example

beforeafter

Existing baseline

PT-101	AI	Separator pressure	101
FT-102	AI	Separator flow	102
TIC-204	AO	Separator temperature	204

Tie-in delta

ESDV-307	DO	Inlet ESD valve	307
FT-201	AI	Meter run flow	201
PT-105	AI	Discharge pressure	105

3 existing·3 new·merged 6

What the tie-in pass produces.

Three documents, all from the same workspace. The baseline you only pay for once, the Change Report your panel shop reads, and the merged tag table your engineering team imports.

Existing I/O baseline.

The first extraction pass returns the full I/O list of the facility as it stands today. Every instrument, signal class, equipment owner, and source-page reference is preserved. Re-uses cached results when re-run on the same drawings, so the baseline only pays once.

Before● ready

Tie-in delta report.

Compare the baseline against the post-tie-in extraction. The Excel Change Report opens with a Summary sheet plus colour-coded Added, Removed, and Modified tabs. Tag number, instrument type, signal class, description, location, and page reference travel through on every row.

Delta● ready

Merged tag table.

The full merged I/O list exports to TIA Portal XML, Studio 5000 L5X, or PLCCreator CSV. New rows carry the same signal-class assignment and module-sizing fields as the baseline, so the engineering team imports one file and runs.

Merged● ready

How a tie-in runs through Tagsight.

01
Upload the existing package.
Drag the current P&IDs, instrument indexes, datasheets, and loop diagrams into a workspace. Vector PDFs from CAD process fastest. Scanned legacy drawings are read at high resolution and flagged for review on uncertain rows.
Vector + scanned · Mixed packages OK
02
Mark the new tie-in scope.
Open the v3 review canvas. Drag a rectangle around the new equipment area on each affected drawing. Tagsight re-extracts just that region and merges the new rows into the project. Every drag is logged in the project audit drawer and reversible.
Free re-analyze · 25 per project
03
Export the merged I/O list.
Run the comparison against the baseline. The Excel Change Report lands in seconds. Then pick TIA Portal XML, Studio 5000 L5X, or PLCCreator CSV. The engineering team imports the merged file directly on their workstation. The originals stay in the customer EDMS.
Local-first import · Source kept in your EDMS

Tie-in I/O lists, extracted from the existing P&ID set.

OutputExcel Change Report + merged tag tableStandardISA 5.1 + corpusWorkflowRegion re-analyze + revision diff

Tie-in I/O lists, extracted from the existing P&ID set.

What the tie-in pass produces.

Existing I/O baseline.

Tie-in delta report.

Merged tag table.

How a tie-in runs through Tagsight.

Upload the existing package.

Mark the new tie-in scope.

Export the merged I/O list.

Tie-in I/O lists, extracted from the existing P&ID set.

What the tie-in pass produces.

Existing I/O baseline.

Tie-in delta report.

Merged tag table.

How a tie-in runs through Tagsight.

Upload the existing package.

Mark the new tie-in scope.

Export the merged I/O list.