The CPU 412-5H has:

• A powerful processor:
  The CPU achieves command execution times as low as 31.25 ns per binary command.
• 1 MB RAM (512 KB for program, 512 KB for data);
  load memory for user programs and parameterization data of the S7-400H F/FH automation system; high-speed RAM for sequence-relevant sections of the user program
• A memory card:
  For expanding the integrated load memory. In addition to the program itself, the information contained in the load memory also includes configuration data for the S7-400H F/FH, which is why it requires about twice as much memory space. The result is that:
  • The integrated load memory is not sufficient for large programs, which is why the memory card is often required.
    RAM and FEPROM cards are available (FEPROM for saving data even when power supply is disconnected).
• Flexible expansion options:
  Up to 131 072 digital and 81 932 analog inputs/outputs.
• Combined MPI/PROFIBUS DP interface:
  The MPI enables the creation of a simple network with up to 32 nodes and a data transfer rate of 187.5 kbit/s. The CPU can establish up to 64 connections to nodes on the communication bus (C bus) and the MPI.
  The PROFIBUS DP master interface enables a distributed automation configuration with high speed and simple handling. From the user’s point of view, the distributed I/Os are treated like centralized I/Os (same configuring, addressing and programming).
• PROFIBUS DP interface:
  The PROFIBUS DP interface allows a redundant, distributed automation configuration offering high speed and ease of use. From the user’s point of view, the distributed I/Os are treated like centralized I/Os (same configuring, addressing and programming).
• PROFINET interface with 2 ports (switch):
  Support of system redundancy and MRP (Media Redundancy Protocol)
• Mode selector:
  Designed as a toggle switch.
• Diagnostics buffer:
  The last 120 alarm and interrupt events are stored in a ring buffer for diagnostic purposes.
• Real-time clock:
  Diagnostics reports from the CPU are provided with the date and time.

• Block protection:
  In addition to the keylock switch, a password concept protects the user program from unauthorized access. User blocks can also be protected by an encryption process.
• Integrated HMI services:
  In the case of HMI devices, the user only has to specify the source and destination of the data. These are automatically transferred cyclically by the system.
• Integrated communications functions:
  • PG/OP communication
  • Extended communication (simple and high-availability)
• Master-spare switchover programmed by user.

Parameterizable properties

With the STEP 7 tool “Hardware Configuration” and the installed option package S7-400H, the properties and behavior of the S7-400H including the CPUs can be parameterized, e.g.:

• Multi-point interface MPI:
  • Determining node addresses.
  • Startup/cyclic behavior.
  • Definition of maximum cycle time and communication load.
• Address assignment:
  Addressing of the I/O modules.
• Retentive areas:
  Definition of the number of retentive bit memories, counters, timers, data blocks and clock memories.
• Protection level:
  Definition of access authorization to program and data.
• System diagnostics:
  Determination of handling and scope of diagnostics messages.
• Watchdog interrupts:
  Setting the periodicity.
• Configuring of H stations.

Safety-related functions

With the F runtime license, the safety-related F user program can be compiled and run on the CPU. One license is required for each S7-400F/FH system. The scope of delivery includes 2 TÜV (German technical inspectorate) adhesive labels.

Display and information functions

• Status and fault indicators:
  LEDs indicate, for example, internal and external faults and operating statuses such as RUN, STOP, startup, “Master” operating mode, redundancy errors, and test function.
• Test functions:
  The programming device can be used to display signal states in the program execution sequence, modify process variables independently of the user program, output contents of stack memories, run through program steps individually, and disable program sections.
• Information functions:
  The user can obtain information about the memory capacity and operating mode of the CPU, and the current utilization of the RAM and load memory.