Siemens 6ES7211-0AA21-0XB0 Power Supply Module

Siemens 6ES7211-0AA21-0XB0 is a CPU 221 Compact Unit for the SIMATIC S7-200 family, combining a built-in DC power supply with six digital inputs and four digital outputs (6 DI DC/4 DO DC) and 4 KB of code memory plus 2 KB of data memory. The compact module measures 90 x 80 x 62 mm and weighs about 0.27 kg, offering a space-efficient solution for small automation tasks that require a dedicated CPU with discrete I/O. As part of the CPU 221 line, it provides straightforward program storage and execution alongside direct I/O control for basic sensing and actuation. Product listings from Siemens-based distributors consistently describe 6ES7211-0AA21-0XB0 as a SIMATIC S7-200 CPU 221 Compact Unit with a DC power supply, 6 DI DC and 4 DO DC, and 4 KB code/2 KB data memory. In several catalogs, the model is noted as discontinued by the manufacturer, reflecting the aging S7-200 ecosystem across multiple markets.