Mitsubishi FX1S-20MT-001 PLC CPU Module with 20 I/O Points

FX1S-20MT-001: A 20-Point Transistor-Output PLC CPU

The FX1S-20MT-001 is a compact PLC CPU with 20 I/O points built in: 12 inputs and 8 transistor outputs, AC220V supply, transistor output type, outline dimension 75 x 75 x 90 mm.

The MT designation is the part that decides the output type, and it is worth being precise about. A transistor output CPU drives the load through a switching transistor rather than a relay contact. That means faster switching and no mechanical contacts to wear — but it also means the output is not galvanically isolated from the load supply the way a relay output is, which is the one place where substituting a different output type changes behaviour.

Where a relay-output variant is specified in the same slot, the substitution is not always transparent: the isolation characteristic between output common and the supply rail differs.

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Where 20 Points Is Enough and Where It Is Not

12 inputs and 8 outputs covers small standalone machines — a conveyor with a handful of sensors and actuators, a small pump station, a basic sequencing panel. It is not enough once the machine needs expansion, and the point where that becomes true is worth establishing before the machine grows rather than after.

Output Type as a Replacement Decision

On a replacement, confirm output type rather than just point count. Transistor and relay outputs are interchangeable on the point count but not on behaviour: transistor outputs switch faster, have no contact wear, and do not provide the same isolation from the supply rail. Where the original CPU was a relay-output variant, a transistor replacement changes the isolation characteristics of every output on the module.

Supply & terms: Stock status: In Stock · Condition: New · Warranty: One Year · Origin: Japan. Listed by AutoDCS Tech Parts Team · Last updated 2026-10-07.

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