Siemens 6ES5956-0AA12 Printed Circuit Board Assembly

The Siemens 6ES5956-0AA12 is a printed circuit board assembly (PCBA) used as an add‑on board for the SIMATIC S5 family of PLCs, designed for 15‑V operation within legacy automation hardware and intended to slide into compatible S5 backplanes to support supplementary control functions. It is described as an accessory that interfaces with the 955 power supply and the CP 535 interface processor, providing the required board‑level connections to integrate an S5 controller with those components and to extend the capabilities of aging Siemens automation architectures. Multiple retailers and distributors identify the part by its exact catalog number (6ES5956-0AA12) and classify it as a SIMATIC S5 15V module F, reinforcing its role within the older 6ES5/S5 ecosystem. Industry listings consistently designate this item as discontinued, indicating it is no longer produced by Siemens and is primarily encountered in spare‑parts inventories or secondary markets for maintenance of legacy systems.