What the catalog line carries
The RX40NC6H: It sits in the same expansion-module slot class as the rest of the RX line — a drop-in card for a MELSEC rack where the I/O map calls for that exact code, not a generic digital-input substitute.
Sourcing posture for an active module
With current on the listing, the RX40NC6H is specified into the BOM as an active Mitsubishi expansion card; quotes are run to order against an RFQ rather than pulled from a last-time-buy window.