The Schneider BMXDD06420K is a digital I/O module from the Modicon M340 series, running on 24 VDC. It provides 8 digital inputs and 8 digital outputs (relay type), configurable per application needs, with backplane communication to the CPU rack. The 4-channel count reflects the grouping of I/O pairs for wiring convenience.
Mounts on standard DIN rail inside the control cabinet. The backplane interface means it connects directly to the M340 rack bus — no fieldbus wiring needed for I/O data. Rated for 0 °C to 60 °C ambient, so it lives comfortably in a ventilated enclosure alongside drives and contactors.