Nokta Industrial
 Automation Systems

CPU 317F-2 DP
  • Password protection;
    a password concept protects the user program from unauthorized access.
  • Diagnostics buffer;
    the last 100 errors and interrupt events are saved in a buffer for diagnostics purposes.
  • Maintenance-free data backup;
    the CPU automatically saves all data in case of power failure so that the data are available again unchanged when the power returns

Configurable attributes

STEP 7 can be used to parameterize both S7 configurations and the properties and responses of the CPUs:

  • MPI multipoint interface;
    determination of node addresses.
  • Restart/cycle time behavior;
    stipulation of maximum cycle time and loading.
  • Clock bit memory;
    address setting
  • Protection level;
    definition of access rights to program and data.
  • System diagnostics;
    definition of the handling and scope of diagnostics messages.
  • Watchdog interrupts;
    setting of periodicity
  • Time-of-day interrupts;
    setting of date and time of start and periodicity
  • PROFIBUS DP master/slave interface;
    user-oriented address allocation for distributed I/O.

Indication and information functions

  • Status and error indications;
    LEDs indicate e.g. hardware, programming, time, I/O or bus errors, as well as operating states such as RUN, STOP and restart
  • Test functions;
    the PG can be used to display signal states in program execution, modify process variables independently of the user program, and read out the contents of stack memories.
  • Information functions;
    you can use the PG to obtain information about the storage capacity and operating mode of the CPU as well as the current loading of the main and load memories, current cycle times and diagnostic buffer contents in plain text.

Integrated communication functions

  • PG/OP communication
  • Global data communication
  • S7 basic communication
  • S7 communication (server only)

Sequential function chart

The CPU provides many extensive system functions for diagnostics, parameterization, synchronization, alerting, time measurement, etc.
Details can be found in the manual.


The safety-related communication and standard communication between the central controller and the distributed stations is conducted over PROFIBUS DP. The specially developed PROFIBUS profile PROFIsafe allows the transmission of user data associated with the safety function within the standard data telegram. Additional hardware components, e.g. special safety buses, are unnecessary. The required software is either integrated in the hardware components as an extension of the operating system, or must be loaded into the CPU as a certified software component.

Mode of operation

The safety functions of the F CPU are contained in the CPU's F program and in the fail-safe signal modules. The signal modules monitor the output and input signals by means of discrepancy analyses and test signal injections. The CPU monitors proper operation of the PLC by performing regular self-tests, instruction tests and logic and sequential program flow control. In addition, the I/O is checked by requesting signs of life. If an error is diagnosed on the system, the latter is moved to a safe state. An F runtime license is not required for operation of the CPU 317F-2 DP.


The CPU 317F-2 DP is programmed in the same manner as other SIMATIC S7 systems. The user program for non fail-safe plant sections is created with the proven programming tools such as STEP 7.

SIMATIC S7 Distributed Safety option package

The "S7 F Distributed Safety" option package is required to program the safety-relevant parts of the program. The package contains all the functions and blocks required to create the F program. The F program with the safety functions is linked in F-FBD or F-LAD or using special function blocks from the F library. Use of F-FBD or F-LAD simplifies plant planning and programming and, because of the uniform and cross-vendor presentation, the acceptance test too. Programmers can concentrate completely on configuration of the safety-relevant application without having to use additional tools.

Copyright 2009 - Nokta Industrial. All rights reserved.
Tel: 0090-212-272-5880
Fax: 0090-212-272-5868