6ES7 414-4HM14-0AB0

Siemens 6ES7 414-4HM14-0AB0 is the CPU 414-4H processing unit for S7-400H and S7-400F/FH configurations. Its 2.8 MB working memory is divided equally between program and data, with 1.4 MB assigned to each. The working memory is not expandable. Integrated RAM load memory is 256 KB, and compatible RAM or FEPROM expansion supports up to 64 MB for the loadable application.

The CPU provides an MPI/PROFIBUS DP interface, a separate PROFIBUS DP interface and two connections for synchronization modules. These connections serve different roles: the RS-485 interfaces provide engineering, operator and distributed-I/O communication, while the synchronization connections belong to the configured H-system arrangement. Fault-tolerant operation depends on the complete paired CPU, synchronization and I/O configuration; a single CPU does not by itself establish system redundancy.

The V4.5 technical configuration uses STEP 7 V5.3 SP2 or later with the appropriate hardware update. The CPU receives power from the S7-400 system power supply, draws 1.4 A typically from the 5 V backplane and dissipates approximately 6 W. Battery backup supports retention of the complete working and load memory. During replacement, match the firmware, memory content, synchronization hardware and existing engineering configuration before checking system diagnostics and redundancy operation.