The Siemens 6ES7924-0CL20-0BA0 is a connection module for SIMATIC S7-300 and S7-1500 systems, designed specifically for digital I/O modules. It screws onto a 35 mm or 15 mm DIN rail — the 15 mm option is handy when the panel backplane is already tight on vertical clearance. It carries 28 screw terminals: 8 for I/O signals, 10 for L+ (24 V DC supply), and 10 for M (common). Rated at 1 A per channel with a total current limit of 4 A across all terminals — so if you're feeding a dense bank of inputs, watch the aggregate draw doesn't exceed that 4 A ceiling.
Mounting and wiring reality
Screwdriver blade width is 3.5 mm — standard for this class of terminal block. The module has no shield connection, no PE connection, and no disconnector — it's a straight pass-through. If your panel spec calls for shielded cable termination, you'll need a separate grounding terminal block nearby.