The Siemens 6ES7321-1BH01-0AA0 is a digital input module for the SIMATIC S7-300 automation system. It provides 16 inputs rated at 24 V DC with a typical input current of 7 mA per channel and connects field sensors or switches to the PLC backplane bus. The module occupies one slot on the S7-300 rack and is commonly installed in machine control panels or process skids where reliable 24 V DC discrete signal acquisition is required.
