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GX WORKS3 • FX5U / GX WORKS3

Should I compile an FX5U project before writing it?

Yes. Rebuild or compile the edited project, resolve relevant errors and warnings, then compare and write only the intended data.

Practical explanation

Compilation catches syntax and consistency issues before transfer.

A successful compile does not prove that machine behavior is safe, so functional review is still required.

Check in this order

  1. 1Review changed networks and devices.
  2. 2Compile the project.
  3. 3Check warnings, parameters and labels.
  4. 4Make a backup before transfer.

Safety: Test online changes under an approved commissioning plan with the machine in a controlled state.

Last reviewed: 2 October 2026

Official source: GX Works3 Operating Manual

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