What it is and where it fits
The Siemens 6ES7923-0BC50-0DB0 is a pre-assembled shielded round cable that connects the front connector module to the connection module on SIMATIC S7-300 and S7-1500 systems. It carries 16 conductors at 0.14 mm² each, terminated with IDC connectors at both ends, and runs 2.5 m between the two modules. Rated at 24 V with a maximum of 60 V, this cable is designed for both digital and analog I/O signals — the braided shield keeps noise off analog lines in the cabinet. The 8-channel count per cable matches the typical 8-channel I/O module footprint, so one cable per module is the standard wiring pattern.