1. A "Machine project".
A machine that runs through several sequence steps to manufacture one part.
The program must use a state machine.
The program must have both fully automatic mode, semiautomatic single-step mode, and fully manual mode.
The HMI must display step information, including information about the next pending step.
Settings must be handled by recipes.
Errors must be handled intelligently. Error codes must be displayed on the HMI.
Each manufactured part must be logged to a database.
2. A "Process plant" project.
A plant that consists of many motors, pumps, acuators and sensors distributed over a wide area.
The program must consist of reuasable code objects for each type motor, pump, actuator etc.
On the higher level, a proces control with one or more PID loops controls the actuators to achieve the desired process.
It is possible to split the project into continous process and batch process.
The HMI must allow the monitoring and control of the process on the higher level.
The HMI must allow the monitoring and parameter adjustment of the individual actuator and sensor on the lower level.
Error codes for both the higher level and the lower level must be displayed on the HMI.
There must be trend curves on the HMI for the control loops.
All important process parameters and sensor values must be logged to a database.
If the above is too much to swallow, it can be split into sub-projects.
What the machine or the process plant actually do, your or your students can discuss.