CPU 416-2 — what it is and what it does
The Siemens 6ES7416-2XN05-0AB0 is a SIMATIC S7-400 CPU 416-2 with 5.6 MB work memory, designed for mid-to-large control applications in the S7-400 rack. It supports the full IEC 61131-3 programming languages: LAD, FBD, STL, SCL, GRAPH, and CFC, so any Siemens programmer can work with it. The CPU has a single PROFIBUS DPV1 interface (RS 485) and one MPI port, plus routing capability when the interface is active.
Key ratings and what they mean for fit
The CPU handles 244 bytes of process input and 244 bytes of process output, which sets the I/O image size for fast cyclic updates. For larger data transfers, the RDREC (SFB 52) and WRREC (SFB 53) blocks allow up to 8 records per interface, with a total of 32 across all external interfaces — enough for a distributed PROFIBUS network with several DP slaves. The FM (fault monitoring) is limited by the number of slots and connections, meaning the diagnostic buffer depth depends on your rack configuration. Operating temperature range is 0 °C to 60 °C, so it fits standard control cabinets without derating.
ATEX and approvals — what's on the nameplate
This CPU carries ATEX II 3G Ex nA IIC T4 Gc, meaning it's approved for use in Zone 2 gas atmospheres (non-sparking, T4 temperature class). It also has cULus and CE marks, so it ships into North American and European panels without extra paperwork. The GSD file for PROFIBUS configuration is available online.
Mounting and integration notes
Width is 25 mm, height 290 mm, depth 219 mm — it occupies one slot in the S7-400 rack. The CPU is isolated, so no grounding issues between the backplane and the PROFIBUS segment. For CP (communication processor) expansion, you can install up to 4 CP443-1 modules in the central controller, but no mixed operation of CP443-1 EX40 with EX41/EX20/GX20. Point-to-point CPs (CP 440, CP 441) are limited by slots and connections.
Sourcing reality
This CPU is an active Siemens catalog item. For a BOM freeze or a new build, quote to order — we source it through Siemens distribution.