CPU 414-2: 16 inputs, ATEX-rated, isolated backplane
The Siemens 6ES7414-2XK05-0AB0 is an S7-400 CPU with 16 digital inputs and a 244-byte process image for inputs and outputs each — the process image size governs how many I/O bytes the CPU can update in a single cycle, so a 244-byte limit means you can map up to that many input and output bytes without adding a second scan. Rated for 0 °C to 60 °C ambient, with an ATEX II 3G Ex nA IIC T4 Gc certification — this CPU is built for environments where explosive gas atmospheres may occur infrequently, such as in chemical or pharmaceutical plants, and the 60 °C ceiling means it handles the heat inside a sealed panel without derating. The backplane is isolated, and the CPU carries both CE and cULus marks — it fits into panels destined for North America or Europe without a separate agency review.
Programming and communication: LAD, FBD, SCL, STL, GRAPH, CFC
Programmable in LAD, FBD, SCL, STL, GRAPH, and CFC — the full S7-400 language set — and configured via STEP 7. The CPU also supports CFC (Continuous Function Chart) for block-oriented process control. Onboard MPI and RS 485 interfaces, plus DPV1 capability — the DPV1 protocol allows acyclic data exchange for parameterisation and diagnostics without interrupting cyclic I/O. Communication block limits: 8 RDREC (SFB 52) and 8 WRREC (SFB 53) per interface, with a total cap of 32 across all external interfaces. The (SFC 59) and (SFC 58) blocks are also limited to 8 per interface. For CP443-1 Ethernet modules, a maximum of 4 can be installed in the central controller. Supports forcing, routing, and the RDSYSST system status block — forcing lets an engineer override an input or output value during commissioning without changing the program, while routing allows the PG/PC to reach all network nodes through the CPU.
Physical fit: 25 mm wide, 290 mm tall, 219 mm deep
The module is 25 mm wide, 290 mm tall, and 219 mm deep. Function Manual (FM) is limited by the number of slots and connections — this is a standard S7-400 constraint: the CPU can address as many FM modules as the rack slots and backplane current budget allow, not a hard CPU limit.