The Siemens 6ES7414-3FM06-0AB0 is a CPU 414-3 PN/DP for the S7-400 rack — a mid-range controller that handles 244 byte inputs and 244 byte outputs across the backplane, with an integrated PROFINET interface and a PROFIBUS DP port. It supports CFC, FBD, LAD, SCL, STL, and GRAPH programming languages, plus IRT for deterministic PROFINET IO — meaning it can run a mix of continuous-flow logic and motion-synchronized axes on the same ring without a separate motion controller. The CPU is isolated and supports forcing, routing with the interface active, and up to 4 CP443-1 communication processors in the central controller — but no mixed operation of EX40 with EX41/EX20/GX20 variants.
FM and Communication Limits
The FM (function module) capacity is limited by the number of slots and the number of connections — not a fixed count, so the actual ceiling depends on the backplane slots available and the total communication load from all modules. Point-to-point CPs (CP 440, CP 441) are also limited by slot count and connection count. The CPU supports DPV0 but not DPV1, which means it can exchange cyclic I/O data with PROFIBUS DP slaves but cannot handle acyclic parameter-channel writes from the master — a constraint if the field devices rely on DPV1 for configuration. UDP and TCP/IP are available via the integrated PROFINET interface and loadable function blocks. RS 485 is supported. MPI is not supported on this CPU — so any legacy MPI-only devices need a separate gateway or a different CPU.
S7-400 Rack Fit and Dimensions
The CPU occupies a single slot in a standard S7-400 rack. Dimensions are 50 mm wide, 290 mm high, and 219 mm deep — it fits the standard 19-inch rack footprint and leaves room for adjacent I/O modules or CPs. The GSD file for PROFIBUS DP configuration is available at the Siemens support portal — download it before commissioning to ensure the master can identify the CPU as a DP slave.