PLC Tag List Cleaner and Name Checker

Paste a list of tag names, one per line, and get a clean, consistent list that follows your PLC's naming rules, with every change explained.

How it works

Each line is cleaned in the same order, and the Notes column lists everything that changed so nothing happens silently:

1. Spaces and symbols become underscores (optional).
2. For Allen-Bradley and generic rules, repeated underscores are collapsed and a trailing underscore is removed.
3. A name that starts with a digit gets a leading underscore.
4. Letters are converted to your chosen case.
5. Names that are the same after cleaning are numbered (_2, _3, and so on), and the first one is left as is.
6. Names that are longer than the limit, or still contain characters the format does not allow, are flagged for you to fix by hand. The tool never silently shortens a name, because two shortened names could collide.

Worked example

Motor 1 Start becomes MOTOR_1_START. A second Motor 1 Start becomes MOTOR_1_START_2. 1st Stage Valve becomes _1ST_STAGE_VALVE because a Logix tag cannot start with a digit. Tank__Level_High_ becomes TANK_LEVEL_HIGH.

Common questions

Are these rules exactly right for my software version?

They follow the commonly documented limits: Logix tags start with a letter or underscore, use letters, numbers and underscores, stay within 40 characters and avoid repeated or trailing underscores. TIA Portal is more permissive, and the tool only enforces its length limit. Check your software version's documentation, and use your site's own naming standard where it has one.

Is my list uploaded anywhere?

No. The cleaning runs in your browser.

This tool is provided for convenience. Review the cleaned names before using them in a project.