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Version Link compares two L5X exports of a Rockwell Automation Logix program. Drop them on the compare page, summarise one file on the overview page, or browse one file's logic, tags and I/O on the browse page.

What is compared

Ladder routines: Added, removed and changed rungs, with rung numbers and comments. Changed instructions are highlighted inside the rung.
Structured Text: Added, removed and changed lines.
FBD and SFC: Sheets and steps by name. The logic inside them is not compared.
Tags: Controller and program tags added or removed, and changed values. Every tag value on request.
Modules: Added, removed and changed modules, including catalogue number and parent.
Add-On Instructions: Added, removed and changed, including parameters.
Data types: UDTs added or removed, and members added, removed or retyped.
Tasks and programs: Added, removed and changed, including task type, rate, priority and scheduled programs.
Controller: Processor, software revision, last saved and export dates.

Limits

Files up to 50 MB each.
5 comparisons or overviews a day, and 20 PDF downloads a day.
A file that takes more than 2 minutes to read is stopped.

Your files

The free tool reads files in memory and discards them. Nothing is written to disk or a database, and file names are not logged. Programs uploaded to a controller through Portal are stored encrypted.

Connect an AI agent

Claude, Cursor and other MCP clients can read stored programs through a read-only endpoint: controllers, versions, routines, tags, where a tag is used, the I/O map and what changed between versions. Answers cite rungs as Program/Routine#N. Nothing can be changed, downloaded or sent to a controller.

Create a key in Portal under Developers, API keys, with the Version Link scope Read programs. A key limited to a site reads that site only. Each call is logged for your organisation's administrators, and a key can make 120 calls a minute.

Claude Code

claude mcp add --transport http version-link https://versionlink.processlink.com.au/api/mcp \
  --header "Authorization: Bearer plk_..."

Cursor and other clients

{
  "mcpServers": {
    "version-link": {
      "url": "https://versionlink.processlink.com.au/api/mcp",
      "headers": { "Authorization": "Bearer plk_..." }
    }
  }
}

Supported controllers

ControlLogix, CompactLogix and GuardLogix projects exported as L5X. ACD files are not supported.