Startup state-machine
Following steps are taken to complete the communication and download the last recipe data to the PLC variables on the machine startup:
- On the startup the PLC does not have any recipe data because the HMI may start a session later. The PLC will set the
DataRequestPLCflag to TRUE and theDataValidPlcflag to FALSE. - The HMI client will read
DataRequestPLCvariable on initialization and setDataRequestPLCActiveHmito TRUE to indicate it has received the request. - The recipe that is saved as the active temporary recipe will be activated from the HMI and will set the values to all the related PLC variables.
- The HMI client will write FALSE to
DataRequestPLCActiveHmiand TRUE toDataRequestPLCQuitHMIto indicate the complete activation. - The PLC will remove the request by resetting
DataRequestPlcto FALSE.