Controlling the handshake bit

Control of the handshake bit is recommended to check whether the data of the lower-level controller is still correctly received, processed, and signaled. If more than one consistent block is used for the software module (11 or more path segments for the standard profile), the handshake bits are also used to establish consistency between the blocks. The following logic must be implemented on the higher-level controller for this purpose:

IF Handshake_PI = Handshake_PO THEN

// Process output data and process input data are only the same if the last telegram has been processed consistently.

  Invert all Handshake_POs

ELSE

  Time monitoring, with timeout error

END_IF