What It Is and Where It Fits
The Siemens 6ES7924-2AK20-0BA0 is a connection module designed for the SIMATIC S7-1500 target system, specifically for digital I/O modules. It provides the wiring interface between field devices and the I/O module, with an infeed function to supply the module's load group. It mounts on standard 35 mm or 15 mm DIN rail, in any position, and uses screw-type terminals. The enclosure is grey, sized 100 mm wide × 76 mm high × 60 mm deep, with a single terminal level at the top.
Key Ratings and What They Mean for Fit
Rated for 24 V DC (maximum 28.8 V DC) and 1 A per terminal, with a total current limit of 2 A across all terminals. This means the module can handle up to 2 A total load on its I/O circuits — enough for a bank of sensors or small actuators, but not for high-current outputs. The 40 terminals break out as 32 I/O points plus 4 each for L+ and M, so you get a full 32-channel digital I/O connection in one module. The screw terminals accept stranded wire from 0.5 to 2.5 mm², and each connection can take up to two wires (with a ferrule for the internal system connection). Maximum cable length between the front connector module and this connection module is 30 m — useful for remote I/O cabinets.
Integration Notes
No shield connection or PE connection on this module — grounding happens at the I/O module or cabinet level. Pollution degree 2 and overvoltage category II mean it's suited for clean, controlled environments like a panel with basic climate control. Operating temperature range is -30 to +60 °C, storage -40 to +70 °C. The module includes an infeed function, so it can supply power to the connected I/O module's load group without an external distribution block. No end cover plate is required, and a 3.5 mm screwdriver blade is specified for the terminals.