CPU 416-2 for S7-400 — what this order code carries
The Siemens 6ES7416-2FN05-0AB0 is a CPU 416-2 for the S7-400 platform, 25 mm wide and 290 mm tall, depth 219 mm — a single-wide module that fits the standard S7-400 rack without crowding adjacent slots. It supports the full IEC 61131-3 language set: CFC, FBD, LAD, SCL, STL, and GRAPH, plus MPI and RS 485 for local programming and peer-to-peer links. The CPU is isolated and carries cULus and CE marks, plus ATEX II 3G Ex nA IIC T4 Gc for use in Zone 2 gas environments — a rare combination on a S7-400 CPU that simplifies panel certification for combined industrial and hazardous-area lines.
Interface limits and communication capacity
Each external interface supports up to 8 (SFC 59) and 8 (SFC 58) operations, and 8 RDSYSST calls; the DPV1 interface handles 8 RDREC (SFB 52) and 8 WRREC (SFB 53) per interface, with a global cap of 32 across all external interfaces. Up to 4 CP443-1 Ethernet processors are allowed in the central controller, but mixed operation of CP443-1 EX40 with EX41/EX20/GX20 is prohibited. Point-to-point CP 440 and CP 441 modules are limited by slot count and connection count respectively; the CPU itself does not impose a hard cap beyond the rack's physical limits.
Process image and I/O addressing
The CPU provides 244 bytes each of process-input and process-output image, with a default preset of 120 bytes. Up to 16 SFBs are available for high-level communication and system functions, and forcing is supported for commissioning and fault simulation.