The Mitsubishi FX5U-64MT/ESS is a MELSEC iQ-F CPU module with 32 inputs (24 V DC sink/source) and 32 transistor source outputs. This is a current-production part.
How it compares: source vs. sink output
The closest sibling is the FX5U-64MT/ES, which shares the same 32-point DC input card and AC power supply but uses transistor sink outputs instead of source. The /ESS suffix here drives sourcing outputs—common for positive-logic load wiring in many Asian and European panels. If your existing field wiring expects a sourcing output module (current flows from output to load), the /MT/ESS drops in with no rewiring. If the current build uses sink outputs, you need the /ES variant.