The system in Figure $1$ shows a plant pumping and water treatment system. The system is to be connected to the Internet for monitoring externally.

There is an analogue height sensor to measure the height of fluid in Tank $2.$

Each tank has an upper and lower limit connected using the ASi Fieldbus interface.

The temperature in the heaters is monitored and displayed on a HMI connected via the Profibus DP interface.

The HMI also has the Start$/$Stop functions as part of its control.

This system is used for questions A$.1$ and A$.2$