spi (FB)

FUNCTION_BLOCK spi

This function block is the base class for SPI devices controlled via the SPI device /dev/spidev0.0. It is meant to be extended by other function blocks that overload the body and the following methods/properties and replace it with their specific implementation, always including a call of the base implementation with super^.<MethodName>() :

• body (general handling, start-up)

• AfterReadInputs (reading input data)

• BeforeWriteOutputs (writing output data)

• Initialize [optional] (used to read parameters from the configuration)

• Operational [optional] (used to signal the status of the device)

The body of this FB is called by the methods AfterReadInputs and BeforeWriteOutputs, where _xAfterReadInputs indicates the caller. Use _iState to control your statemachine. A value of 10 by default indicates that the device is operational. Do not forget to call the base implementation with super^(), where the diagnosis indicators are set according to the Operational property.

Properties:

Operational

Methods:

AfterReadInputs

BeforeWriteOutputs

transfer

transferExt

Structure:

• connector
  • AfterReadInputs (Method)
  • BeforeWriteOutputs (Method)
• internal
  • transfer (Method)
  • transferExt (Method)
• status
  • Operational (Property)