The Siemens 6ES7922-3BD20-0AC0 is a 40-pole front connector with pre-wired single cores, purpose-built for SIMATIC S7-300 digital I/O modules. It terminates the field wiring to the module via a screw-type terminal block on the enclosure side, with the cable assembly running 3.2 m to the field device. The 40 poles match the full channel count of a 40-channel digital input or output card, so one connector handles the entire module's field wiring in a single plug.
Rated at 24 V with a maximum of 30 V, this connector is designed for the 24 VDC control voltage standard on S7-300 digital I/O. The 30 V ceiling covers the typical 24 V nominal plus tolerance, but it won't handle 48 V or 120 V field signals — stay within the 24 VDC domain. The 0.5 mm² conductor cross-section (H05V-K wire) is sized for signal-level currents on digital inputs and outputs; it's not rated for power distribution.
Installation notes
The screw-type terminal on the enclosure side accepts the pre-wired single cores, which are numbered consecutively 1 to 40 for clear identification. The cable sheath is blue PVC, outer diameter 2.2 mm per core. The connector plugs directly into the S7-300 module's front interface; no additional wiring between the connector and the module is needed. Operating temperature range is 0 to 60 °C, storage from -30 to +70 °C.