What Exactly Is the SIMATIC S7-400 and Who Needs It? Siemens built the SIMATIC S7-400 for engineers who deal with really demanding production lines or process plants. Think power stations, oil refineries, or car manufacturing. This controller is modular, which means you can mix and match parts depending on what your machine needs. Back in May 2017, Siemens released the ST 400 catalog showing all t...
