SAFEPROG: Modern IEC 61131 PLC programming for safety applications according to IEC 61508 (up to SIL3)

SAFEPROG, the safe IEC 61131 programming system and SafeOS, the safe high-performance runtime system: Two perfectly coordinated and certified software components which enable manufacturers of safety controls to produce a complete system according to the requirements of the IEC 61508 (up to SIL 3) with significantly less effort.

SAFEPROG: Safety through clarity

A clear user interface, simple handling of the entire programming system, open arrangement of all important functionalities, clear marking of safe functions and function blocks as well as non-safe variables, ... all these properties of SAFEPROG increase safety. This way, when working with SAFEPROG you can focus on the essential: Programming of your safety application.

SAFEPROG: Overview of features

Regarding its easy handling and its functional range, the safe PLC programming system SAFEPROG is particularly adapted to the specific requirements of the safety technology. A multitude of provident and error-detecting measures ensure safe programming on the PC:

• Diversified software architecture ensures highest reliability of the safety functionality already in the programming system
• User management with definable access rights
• Password protection of the project and control
• Logging of user actions
• Special data types for the safety technology (e.g. SAFEBOOL, SAFEINT)
• Color marking of different function blocks
• Easy assignment of different project implementation states/releases using time stamps and checksums
• Parameterization of safety-related device functions using SAFEGRID as integral part
• Integrated report for validating the safety functionality of the machine or system
• C interface for complex safety function blocks
• Simulation of the program logic including time sequence
• Native machine code

Furthermore, SAFEPROG offers you all usual features of modern IEC 61131 PLC programming systems such as safety-related editors for developing graphical code and handling variables as well as wizards, cross references or online operating modes for commissioning the SafePLC.

The development of the program logic is done in a few simple steps using the graphical IEC 61131 programming languages Ladder Diagram (LD) and Function Block Diagram (FBD).

Adaptation to your hardware is possible through open interfaces

Three clearly defined interfaces in the SAFEPROG PLC programming system allow easy integration with customer-specific hardware.

• The communication between SAFEPROG and the SafePLC can be handled via already existing TCP/IP or RS232 interfaces. Here, SAFEPROG secures the data for transmission. It is possible to integrate another communication interface.
• The safety-related device topology is integrated into SAFEPROG by means of a customer-specific ActiveX Control.
• Customer-specific device descriptions for the safety-related parameterization can be integrated.

Reproducible logic with the "Enable Principle"

Due to the "Enable Principle", creation of the safety logic is as easy as developing a schematic diagram. The safety control has access to all safety-relevant I/Os and is solely able to set safe outputs. This can occur directly or by enabling (i.e. with permission for) a non-safe signal. The safe component of a system, like for example an emergency stop circuit from the circuitry, is programmed in SAFEPROG.

Example: Safety control enables a non-safe signal of the standard PLC.
 

Plug & Play with already certified PLCopen function blocks

KW-Software offers an extensive library in combination with SAFEPROG, providing 20 function blocks for the safety technology which are already certified according to the PLCopen safety specification 1.0.

The library contains all important safety functions such as Emergency Stop, Safety Door, Two Hand Control, External Device Monitoring, Mode Selector and many more. The inputs and outputs of these function blocks only need to be connected to the I/O terminals for the desired function to be available.

The use of standardized and already certified safety function blocks considerably simplifies the planning and certification of a machine or plant. Extended and additional safety functions can be programmed in user-defined function blocks.

 [Standardized PLCopen function blocks]

The bus navigator integrates the field level

Code editor for the IEC programming languages FBD/LD with wizard

Select the methods that are best suited for your application and use the editor functions with which you develop your program code in the IEC 61131-3 programming languages (FBD) and/or ladder diagram (LD) the fastest.

• Mixing of the graphical languages LD and FBD in one worksheet
• Alignment of objects by using an adjustable grid
• Display of the execution order for blocks and networks
• Inserting any number of new elements in already existing networks
• Moving individual objects or entire object groups
• Opening the code of user-defined functions and FBs via double-clicking on the object icon
• Different colors for functions and FBs of different origin (user FBs, IEC FBs, firmware FBs)
• Easy operation of the editor also via the keyboard
• Inserting functions and function blocks using the Edit Wizard (displayed on right side in the image)
• Tooltips with description of the process data item to which the variable is connected

Grid-based variables editor with error detection

Variable declarations are organized in grids with which the declarations can be handled much more easily and safely. Each grid line contains a variable or instance declaration, each grid column represents a variable property. This way the grid reflects the complete declaration syntax according to IEC 61131.

The variables grid provides decisive advantages:

• Fast and easy declaration of variables and instances.
• Partial selection of variable properties from combo boxes (see image above). This way syntax errors are avoided, as typing errors are excluded on the one hand and on the other hand, no illegal data types or data ranges can be selected.
• Co-dependencies of different variable attributes are detected and taken into account, so that only meaningful settings can be defined.
• Entries that are suspected being faulty (like for example variable names used twice or non-connected global variables) are detected by the editor and the respective fields are immediately highlighted in color (see wrong initial value of the TIME variables in the image above).

PLC control dialog: Control and display

Integrated debugging and commissioning tools

SAFEPROG has powerful functionalities for debugging and commissioning of the safe PLC program:

• Cross references
  If desired, the SAFEPROG cross reference window displays each program location in which you used a variable and will guide you to the respective code position or the declaration of the variables via mouseclick.
• Display of online values in the safe PLC mode
  While the SafePLC is executing the program, you can open code and variable worksheets and display the variable status. The variable status is an online monitoring of worksheets, as the current variable values are read cyclically from the control and displayed as they are stored in the process memory at the end of a working cycle.
• Watch window
  Insert variables from different POUs into the Watch window and display their online values.
• Forcing and overwriting I/Os
  A dialog gives you the option to force I/Os respectively to a preset value or to overwrite them temporarily for the duration of one process cycle.
• Single cycles
  While the SafePLC is running in debug mode, SAFEPROG allows to execute single cycles. This way, you can verify whether the program behaves as you expected.

Integrated safe PLC simulation with extended simulation mode 

SAFEPROG includes the EasySim safety control simulation with which you can simulate the program execution on the SafePLC if no control is available or if before actual commissioning of the "real" PLC a simulated function test is recommended.

When working with the simulation instead of a real PLC...

• if a target resource is connected, it will not be addressed, i.e., its inputs will not be read and its outputs will not be written.
• you can execute the same steps in the programming system as you would if you were working with the real target system. You can, for example, force/overwrite variables or display online values in the editors as usual. Simulation is executed at the same time in the background.
• inputs can be "activated" directly in the simulation, and the effects on outputs can be monitored, thus simulating the I/Os of the actual hardware.

The simulation offers you the option of "programming" scenarios and applying them at the touch of a button in order to easily implement various system states at the simulation inputs.