What this front connector does on an S7-300 rack
The 6ES7922-3BD20-5AC0 is a 40-pole front connector with pre-wired single cores for SIMATIC S7-300 digital I/O modules. It mates with the 6ES7392-1AM00-0AA0 connector on the module face and brings the field wiring out on a 3.2 m cable bundle — saves you having to hand-wire each terminal at the rack. Rated at 24 V nominal (30 V maximum), it handles the standard S7-300 24 VDC field supply for digital inputs and outputs. The 40 cores match the full channel count of a 40-pin I/O module — no spare pins left unterminated.
Wiring and field connection details
Each core is 0.5 mm² H05V-K, individually numbered 1 to 40 with a white adapter marking, so tracing a field device back to its channel is straightforward during commissioning. The cable sheath is blue PVC, 2.2 mm outer diameter per core, bundled. Termination on the module side is screw-type — no special tool needed beyond a standard screwdriver. The connector housing itself uses a screw terminal on the enclosure side as well. Storage temperature range is -30 to +70 °C; operating range is 0 to 60 °C. The cable is rated for digital signal transmission only — not for analog signals.
Mature lifecycle — still specified into new S7-300 builds and supported for existing installations. Supplied in a VPE of 5 units per package.