What it is and where it fits
The Siemens 6ES7923-5BD00-0EB0 is a pre-assembled round cable that connects a 4×16-pole front connector module on a SIMATIC S7-300 or S7-1500 digital I/O module to a 1×50-pole connection module. It uses IDC connectors at both ends, with a 3 m unshielded PVC round cable, 50 conductors of 0.14 mm² each, and a black sheath of 10.3 mm outer diameter.
What the ratings mean for your BOM
Rated at 24 V and carrying a maximum of 60 V, this cable is sized for the signal-level voltages typical of digital I/O modules — not power distribution. The 3 m fixed length suits cabinet-to-terminal-box runs where a custom-cut cable would add labor and risk a miswire. The 50-pole IDC interface mates directly with Siemens front connector modules (16-pole on the module side, 50-pole on the connection module), so no field termination or stripping is needed. The unshielded PVC construction is fine for digital signals in a clean cabinet; for analog or noise-sensitive paths you would want a shielded variant.