Siemens 6ES7 321-1EL00-0AA0 Input Module 40 Pin

Siemens 6ES7321-1EL00-0AA0 is a SIMATIC S7-300 digital input module (SM321) that provides 32 galvanically isolated inputs rated for AC 120 V, accessed via a single 40‑pole front connector. It is designed to plug into the S7-300 backplane and converts 120 V AC sensor signals into PLC input signals while maintaining isolation between all channels and the module electronics. This 32‑input SM321 module supports independent channels for reliable monitoring of discrete devices such as pushbuttons, limit switches, or proximity sensors in industrial automation systems. By delivering 32 discrete inputs over a compact 40‑pole interface, it helps optimize wiring density in control cabinets and simplifies expansion of S7-300 installations that require 120 V AC logic levels. The product is listed under the order number 6ES7321-1EL00-0AA0 and is part of Siemens' SIMATIC S7-300 family, known for modular digital input solutions that support straightforward integration with standard I/O backplanes.