Siemens 6ES5921-3WB14 Programmable Logic Controller Module

Siemens 6ES5921-3WB14 is a CPU module for the SIMATIC S5/SINUMERIK 3.8 family, specifically a CPU 921WB processor designed to work with the central unit 130WB and the integrated PLC 130WB. It serves as the main control processor within a SIMATIC S5-130WB configuration, coordinating program execution and I/O management through the 130WB backplane. This device is part of Siemens’ legacy S5 hardware lineage, and Siemens’ lifecycle documentation confirms that the CPU 921WB/6ES5921-3WB14 line reached end of life on June 30, 2005, indicating it is not a current-production part. Commonly encountered in older automation setups that rely on the S5-130WB system, the module embodies the characteristics of the mature SIMATIC S5 platform while continuing to fulfill duties in vintage machines and systems that require continued operation of established control logic with the 130WB family.