Siemens 6ES5090-8MA01 S5-90U Compact Controller

Siemens 6ES5090-8MA01 SIMATIC S5-90U Compact Controller is a compact, battery-backed CPU from the SIMATIC S5 family. It provides 10 digital inputs at 24 V DC and 6 relay outputs, and it operates from a mains supply of 115/230 V AC. The unit includes an integrated backup battery and is designed to interface with an IM 90 interface module to connect to S5-100 IO modules, supporting up to six expansion modules for modest expansion of I/O. The 6ES5090-8MA01 order number identifies this S5-90U compact controller configuration, making it suitable for small machine-control tasks and legacy automation projects that require reliable digital input sensing and relay actuation in a compact footprint. Typical applications include stand-alone control of simple machines, interlocks, sequencing tasks, and packaging or machine-tools setups where 24 V DC inputs are read and relays drive actuators, with industry-standard 115/230 V AC power and a battery-backed memory arrangement to retain data between power cycles in the S5-90U system.