The CPU 417-4 has:

• Powerful processor:
  The CPU achieves instruction execution times as low as 0.018 µs per binary instruction.
• 30 MB RAM (of which 15 MB each for program and data);
  fast RAM for parts of the user program relevant to execution.
• Flexible expansion:
  Up to 262144 digital and 16384 analog inputs/outputs.
• Multi-point interface MPI:
  With the MPI it is possible to establish simple networking of max. 32 stations at a data transmission rate of up to 12 Mbit/s. The CPU can establish up to 44 connections to stations of the communications bus (C bus) and the MPI.
  Note:
  If the PROFIBUS DP interface and MPI interface are operated simultaneously, it is only possible to connect the following bus connector to the MPI interface:
  
  • With socket: 6ES7 972-0BB42-0XA0
  • Without socket: 6ES7 972-0BA42-0XA0
• Mode selector switch:
  Designed as toggle switch.
• Diagnostics buffer:
  The last 120 fault and interrupt events are retained in a ring buffer for diagnostic purposes (extendable).
• Real-time clock:
  The date and time are appended to diagnostic messages of the CPU.
• Memory card:
  For expansion of the integrated load memory. The information in the load memory comprises S7-400 parameterization data in addition to the program and therefore requires twice as much memory space. The result is that:
  
  • The integral load memory is not sufficient for large programs, therefore a memory card is frequently required.
    RAM and FEPROM cards (FEPROM for retentive storage) are available
• PROFIBUS DP interface:
  The PROFIBUS DP master interface allows a distributed automation configuration offering high speed and ease of use. From the user's point of view, the distributed I/O is treated as central I/O (same configuring, addressing, and programming).
  Mixed configuration: SIMATIC S5 with SIMATIC S7 as PROFIBUS master to EN 50170.
  Note:
  If the PROFIBUS DP and MPI interface are operated simultaneously, it is only possible to connect the following bus connectors to the MPI interface:
  
  • With socket: 6ES7 972-0BB42-0XA0
  • Without socket: 6ES7 972-0BA42-0XA0
• Two additional slots:
  Two additional PROFIBUS DP master systems can be connected via IF 964-DP interface modules.