CPU 414-2 for the S7-400 rack
The Siemens 6ES7414-2XG03-0AB0 is a CPU 414-2 for the S7-400 platform, delivering 64 KB of working memory (code and data) for mid-range control tasks in a distributed rack system. It addresses 244 bytes each of process input and output image, which maps to a typical mix of digital and analog I/O across the rack slots. Two integrated PROFIBUS DP interfaces support MPI and PROFIBUS DP communication, with S7 routing active on the active interface.
Programming and memory constraints
The CPU supports all IEC 61131-3 languages: LAD, FBD, STL, SCL, and GRAPH, plus CFC for continuous function chart engineering — all under STEP 7. Function block memory (FM) is rated at 32 KB, limited by the number of slots and connections in the rack — a hard ceiling for large FB libraries or nested calls. The preset retentivity is set to 'No retentivity', meaning all data blocks and bit memories lose state on power cycle unless explicitly configured otherwise.
PROFIBUS DP and network connectivity
Each of the two integrated PROFIBUS DP interfaces can act as DP master (class 1) or DP slave, with routing enabled when the interface is active. The CPU supports up to 32 overall connections, of which one is reserved for PG and OP (operator panel) access. Via CP (communication processor) modules, up to 10 additional connections are available for LAN or PtP links, limited by the number of slots in the rack.
This CPU 414-2 variant is a mature product in the S7-400 line.