Siemens SIMATIC S7-1200 PLCs & Modules

SIMATIC S7-1200 systems use a CPU to run the program and additional modules where more signals are needed. CPU 1214C, SM 1223 and SM 1234 listings therefore describe different parts of a system, not alternative names for the same PLC.

For a CPU replacement, keep the machine project and installed order number together. For expansion I/O, identify the required signal type and channel arrangement. Siemens 6ES7134 ET 200 analog modules belong to distributed I/O product families and should not be selected as an S7-1200 CPU.