-

Safety-Related Recipe Handling Function Blocks

This topic contains the following sections:

Help version 1.1 / Issue date: 2023.03

Purpose of the recipe handling function blocks

The library RecipeFile contains four safety-related function blocks for the applicative recipe handling of the Safety PLC. They can be used in the safety-related application program.

Applicative recipe handling means that the safety function can be "preset" to a specific operational status or behavior by setting variables, signals and, if necessary, the associated sensors, command devices and actuators to specific values. In this way, for example, the safety function of a plant can be quickly and reliably adapted to a product change or other circumstances.

These values are stored in so-called recipe files, whose file structure is fixed and whose erroneous or abusive falsification can be detected with the help of checksums and signatures. The recipe files are stored in the remanent (Flash) memory (e.g., SD card) of the higher-level standard controller. The number of files and data sets (and therefore the number of recipe values within one file) depends on the Safety PLC. Refer to the topic "Background Information and File Structure" for details on recipe files.

The recipe data is processed by the firmware of the Safety PLC. The function blocks of the library offer the possibility to write and read recipe files from the safety application as well as to delete single data sets within a file or to remove complete files from the flash memory of the standard controller.

The library provides the following function blocks:

Safety information

The safety-related function blocks described here are solely intended for use in the PLCnext Engineer software for creating safety-related code for suitable Safety PLCs. You can only meet your safety-relevant tasks within the safety-related control system if they were integrated into the execution process in a correct and functionally safe manner.

WARNING
Non-conformance to safety function requirements
  • Verify that the safety-related function blocks are only used in accordance with the instructions given in this documentation.
  • Validate the overall safety-related function and thoroughly test the application.

The safety-related function blocks are integrated into the graphical programming interface of the PLCnext Engineer software. Each function block supports a specific function for creating a safety-related application code.

The area of responsibility of the function block manufacturer in terms of the function of a safety-related function block ends at the user interface of the function block, which is represented by its inputs and outputs (formal parameters).

In order to fully execute a safety-related applicative recipe handling, it is your responsibility to connect the inputs and outputs of the safety-related function blocks in PLCnext Engineer in a way that ensures that the values written to or read from the recipe files cannot result in any hazardous situation. The information given in the section "Safety-related verification and use of the recipe function blocks" must be observed

Please read the information and instructions provided carefully and comply with them to ensure you are in a position to use the safety-related function blocks described below in a safety-related manner.

Validity of this documentation

This documentation is only valid for the specified versions of the individual safety-related function blocks.

Using safety-related function blocks

The safety-related function blocks described in this documentation may only be used in conjunction with the PLCnext Engineer software.

Standards and directives

WARNING
Non-conformance to safety function requirements

Verify that your safety-related application implements all additional requirements resulting from applicable directives and standards in order to meet the required safety integrity requirements.

Qualified personnel

When using a Safety PLC and PLCnext Engineer with the safety-related function blocks described here, the following tasks must only be performed by qualified personnel:
This documentation is therefore aimed at:

Within the context of the safety notes in this documentation, qualified personnel are persons who, because of their education, experience and instruction, and their knowledge of relevant standards, regulations, accident prevention regulations, and service conditions, have been authorized to carry out any required operations, and who are able to recognize and avoid any possible dangers.