Siemens 6ES7 131-4BD01-0AA0 Digital Input Module 4DI 24VDC

Siemens 6ES7 131-4BD01-0AA0 digital input module is a 4-channel DI module for the ET 200S distributed I/O system, delivering four 24 V DC digital inputs in a compact 15 mm-wide package. This standard (non-High Feature) device accepts 24 V DC sensor signals and converts them to PLC-ready logic for Siemens SIMATIC controllers when mounted in an ET 200S rack on a DIN rail. The ordering code 6ES7 131-4BD01-0AA0 denotes DI 4x24 V DC, standard, and the unit is commonly sold in packs of five. Each input is designed for standard 24 V DC signaling, enabling straightforward interfacing with typical sensors and switches used in automation tasks. As part of the ET 200S family, it integrates with compatible backplanes and Siemens automation architectures to expand distributed I/O without requiring additional power supplies beyond the module’s 24 VDC domain. The module is listed in Siemens catalogs and product guides as a spare part for ET 200S configurations, reflecting its role as a maintenance-friendly, modular input option for distributed control networks.