Siemens 6ES5188-3UA12 Rack Controller Module

SiemenS 6ES5188-3UA12 Rack Controller Module is a SIMATIC S5 central-controller rack (ZG 188) designed for CD 135U/155U central controllers. This 21-slot backplane rack provides space to mount the central unit and compatible expansion modules, and it ships without a CPU, battery, or manual. The rack is configured for 230 V AC input and an internal 5 V rail to power the backplane, with a current rating of 18 A to support installed modules. Used in legacy S5 automation setups, it serves as the central chassis for CD 135U/155U configurations, enabling organization and distribution of control signals across all slots. For a complete system, pair this rack with the appropriate CD 135U or CD 155U central unit and the necessary expansion or I/O modules to realize a full SIMATIC S5 control scheme.