Relay vs transistor: selecting the right output sibling
The FX5U-32MR/ES: The closest functional peer is the FX5U-32MT/ESS. Same 16 inputs, same AC power, same form factor. The difference: output stage. The relay version (MR) handles AC and DC loads indiscriminately, switching up to the contact rating — good for pilot lamps, contactors, and solenoid coils. The transistor version (MT/ESS) switches at higher speed (kHz range) and is source-output only, suited for driving DC solenoid valves or interfacing with other transistor-input modules. If the target load requires fast pulse output or has a large inductive kick, the MT/ESS fits; otherwise the MR's contact isolation is simpler to commission.
Panel fit and I/O wiring basics
16 inputs at 24 V DC sink/source; 16 relay outputs in groups of two; supply 100 to 240 V AC.
Sourcing this CPU for a BOM freeze
Since the lifecycle is current, the FX5U-32MR/ES is a standard catalog item — no need to chase surplus or negotiate a last-time buy. For a new BOM line, specify the exact order code; there is no functional replacement by an alternative Mitsubishi part number at the same I/O count.