• Block protection:
  In addition to the keyswitch, a password concept protects the user program from unauthorized access. User blocks can also be protected by an encryption mechanism.
• 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 communication 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.:

• MPI multi-point interface:
  
  • Determining node addresses.
  • Startup/cyclic behavior.
  • Definition of maximum cycle time and communication load.
• Address assignment:
  Addressing of 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.

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.