Siemens 6ES5921-3WA13 Processor Module SIMATIC S5-130

The Siemens 6ES5921-3WA13 CPU921 Processor Module is the central processing unit for the SIMATIC S5-130 central controller family. As a CPU921WA module, it plugs into the S5-130 central controller rack to execute PLC logic and coordinate communication with I/O and field devices in legacy Siemens automation systems. The part number 6ES5921-3WA13 identifies this processor module within the S5-130 lineup and aligns with the CPU921 family used in 130-series central controllers. In typical applications, it serves as the control brain for S5-130 installations in manufacturing and process automation environments, enabling reliable program execution and control sequencing on older production lines. Verified characteristics include its designation as a CPU921 WA processor module in the SIMATIC S5-130 central controller family and its association with Zentralbaugruppe 921 hardware for compatible S5-130 racks and backplanes. This module is intended for technicians performing replacement, maintenance, or upgrades of legacy Siemens equipment, helping preserve established control functionality without migrating to newer PLC architectures.