The Siemens 6ES7922-3BD00-0AU0 is a pre-assembled front connector MTA — a 3-meter round cable with a 20-pole front connector on one end and a 50-pole D-sub socket on the other, built for the SIMATIC S7-300 PCS7 MTA system. This is the wiring harness that ties the marshalling panel to the I/O module; the 20-pole front connector mates with the 6ES7392-1AJ00-0AA0 module-side connector, and the D-sub end plugs into the ET200M remote I/O rack. Rated at 24 V with a maximum of 30 V, it handles analog signal transmission (the evidence confirms analog, not digital). The cable sheath is black PVC, outer diameter 10.6 mm, with 0.5 mm² bundled single cores.
The 24 V rated value / 30 V maximum is the working voltage limit on the signal conductors — this is a control-level cable, not power wiring, so it fits the 24 VDC loops common across S7-300 analog input cards. The 3 m length is fixed; no field cutting or re-termination of the round cable is intended. On the enclosure side it terminates to screw-type terminals; in the field it presents a connector strip, meaning the D-sub end is a plug-and-play connection to the ET200M interface. The 20 poles match the channel count (20 channels), so one cable per module.