What this CP1W-EXT01 expansion connector does
The CP1W-EXT01 is a unit adapter — specifically an expansion connector — that lets you add I/O or special-function modules to an Omron CP1 Series PLC rack. It's the physical link between the CPU and an expansion unit, carrying the backplane signals out to the next module in the chain. It belongs to the CP1W accessory family, which covers the connectors, cables, and mounting hardware that make the CP1 platform modular. Without this adapter, the expansion bus stops at the CPU — you can't add a second or third I/O bank.
Designed specifically for the CP1 Series — the CP1L, CP1H, and CP1E CPUs all use the same expansion bus connector. If you're adding an expansion unit to any of those, this is the adapter that bridges the backplane. It ships in a Box package — individual unit, not reel or tray. For a panel build, you order one per expansion slot you need to populate.