Base unit spec at a glance
The FX3U-48MT/DSS is a MELSEC-F series base unit: 24 DC 24 V inputs and 24 transistor source outputs on-board, with program memory of 64K steps held in battery-backed RAM. Expandable to 256 local I/O points (384 including remote), it fits a mid-sized machine slice. Runs a 65-ns LD scan and 642-ns MOV at peak, so cycle time is tight enough for most high-speed sensor arrays. The 35 W draw at 24 V DC and IP10 protection class are typical for a panel-mount PLC. The USB port is listed as OPTION — not populated on every unit; confirm with your order if USB programming is needed. RS-422 is standard.
Panel fit and expansion notes
Mounts with a buffer battery for RAM retention. Ambient range 0 to 55 °C, but consider derating if multiple expansion units are stacked. Expansion bus supports up to 256 local I/O points. Planning the backplane current draw is straightforward at 35 W total from the 24 V DC supply.