This example shows how data can be sent from a program to a component. The program can also receive data by calling public getter methods of the component.

The UpCounterProgram and DownCounterProgram access the CounterComponent with these methods. They use the CounterComponent.GetCommand() to receive an enum of Commands and a setProgress() method to inform the component of the state of the program. Once the program has received a command it will continue to execute this command, and - when finished - execute the CounterComponent.RefreshState() method which will then initiate a state change.

• PLCnext Engineer is installed
• PLCnext Technology SDK for C++ is installed

1. Create one instance of each Program
2. Start the PLCnext Control device
3. Login with PLCnext Engineer Debug or SSH
4. Check progress

You can now see the counters going up and down in the PLCnext - Port List window in PLCnext Engineer. The value of the Down_Counter port on the DownCounterProgram instance will decrement from 255 to zero, then the value of the UP_Counter port on the UpCounterProgram instance will increment from zero to 255.

You can see also the progress in the Custom.log file with tail -f /opt/plcnext/logs/Custom.log.