Compact DC main unit with transistor sourcing outputs
The FX3G-14MT/DSS is a MELSEC-F series PLC main unit with 8 integrated digital inputs and 6 transistor sourcing outputs, all running on 24 VDC. The transistor outputs are sourcing (PNP) logic, so they switch positive-side loads directly — no external pull-up resistors needed for common industrial sensors or small actuators. Program memory is 32K steps stored in EEPROM, with a buffer battery available as an option. The scan time runs 210 ns for a basic LD instruction and 500 ns for a MOV — fast enough for most machine control loops, but the 128 local I/O point ceiling means this is sized for a compact machine, not a distributed line.
I/O expansion and connectivity
The unit is expandable — local I/O tops out at 128 points, and with remote I/O the total reaches 256 points. That gives room for a few analog or specialty modules on the expansion bus without jumping to a larger CPU. Built-in USB and RS-422 ports cover programming and connection to Mitsubishi HMIs or drives. No Ethernet on this base model — if the application needs a network link, an FX3U-ENET or similar adapter rides the expansion bus.
Environmental and power budget
Rated for 0 to 55 °C ambient, draws 19 W from the 24 VDC supply. The IP10 protection class means it is intended for a clean, enclosed panel — not washdown or dust-heavy areas.