Siemens 6ES7 321 1BH50 0AA0 Digital Input Module

Siemens 6ES7 321-1BH50-0AA0 digital input module (SM 321) provides 16 channels of 24 V DC digital inputs for SIMATIC S7-300 PLC systems, enabling direct connection of sensors, pushbuttons, and other discrete devices to the controller without external conditioning. The 16 inputs are organized in a single 16-channel block and use galvanic isolation between channels to improve noise immunity in industrial environments; they connect to the backplane via a 1x 20-pole interface, ensuring robust communication with the CPU and compatibility with standard SM321/SM322 expansion modules. As part of the SM 321 family, the 6ES7 321-1BH50-0AA0 is designed for machine- and process-level discrete I/O tasks, applicable to sensing conveyor lines, end-of-line devices, and general status monitoring within S7-300-based automation systems, and it integrates with Siemens hardware and software ecosystems for scalable I/O expansion.