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FV_PayloadRead** inputs

The FV_PayloadRead** input is present 16 times, numbered from 0 to 15.
Each data set in a recipe file has the size of 64 byte, i.e., consists of 16 values, each 4 bytes in size. Therefore, the set of fail-safe payload values fits into one data set.

At these inputs, the failsafe values (FV) for the recipe data have to be specified: As long as the FB processing is not yet completed successfully (indicated by Done = SAFEFALSE), these FVs are present at the PayloadRead** outputs of the FB.

Data type: SAFEDWORD
Initial value: 0

Connection: Connect literals of the data type SAFEDWORD with the values suitable for your safety application.

Only values which correspond to the results of your risk analysis may be applied to these inputs. Failsafe values must be selected so that they always ensure the defined safe state of the application. Observe the following hazard message.

Example: The limit value for an overspeed shutdown differs within three recipes.
recipe 1= 1500 rpm, recipe 2 = 2000 rpm, recipe 3 = 900 rpm. As result, define the lowest value as failsafe value: FV = 900 rpm

WARNING
Non-conformance to safety function requirements
  • Verify that the payload values applied to the inputs of the function block correspond to your risk analysis and always ensure the defined safe state of the application.
  • Be sure that your risk analysis includes an evaluation for incorrectly setting the payload values at the inputs.
  • Validate the overall safety-related function with regard to the set payload values and thoroughly test the application.