Siemens 6ES7953-8LL31-0AA0 Memory Card: Applications in DCS Systems, Advantages, and Replacement Guidelines I. Which DCS Systems Use This Product? The “6ES7953-8LL31-0AA0” you mentioned is not a dedicated DCS (Distributed Control System) module, but rather a Micro Memory Card from the Siemens SIMATIC series. It is primarily used in the following PLC systems, which often serve as...