4.2. RS 232 serial protocol
The communication through the RS232serial bus is asynchronous and is initiated by the Labview based monitor application.
The Labview application implemented on the PC sends a message that has a three bytes structure. The first byte of the message is the synchronization decimal value 255. The second byte from the serial message is a configuration byte. For a zero byte then we have a data request message and the PC application requires the process variables from the control interface. For other decimal value we have a data writing message and using this byte the PC application specifies the parameter (scaling gain of the fuzzy controller) which will be updated in the control interface. The third byte of the serial message is the updated value of the parameter. If the second byte is zero then also the third byte is zero and the PC waits the next samples of the process variables.