CPU for mid-range S7-400 racks
The 6ES7412-1XF03-0AB0 is a Siemens SIMATIC S7-400 CPU that handles up to 16 function modules (FM), limited by the number of slots and connections in the rack. It addresses 244 bytes each of inputs and outputs, giving it the I/O footprint for a mid-sized distributed control system. Programming options cover LAD, FBD, STL, SCL, GRAPH, HiGraph, and CFC — so whichever language your team prefers for the sequence logic, this CPU supports it. MPI and PROFIBUS DP are onboard for the fieldbus slice; RS 485 is available via the integrated interface.
Physical fit and mounting
The module measures 25 mm wide, 290 mm high, and 219 mm deep — a single-wide S7-400 slot that slides into the rack. The 25 mm width means it consumes one slot position on the backplane; plan for the 290 mm height when clearing the gland plate or enclosure door. One integrated digital input is included, with a resolution of 1 ms. The onboard DI can serve as a fast interrupt input or a simple start-permissive signal without consuming an FM slot.