modelRegulation

Information

The example that really uses the real output of the serial device. All the rest of the family shows quantities that go into the frames; here a quantity comes out of them and drives the model.

The loop is closed and only goes through the two wires of the serial link:

1. the microcontroller sends AT+TEMP; the sensor answers with the value present on valueIn[1];
2. the program computes a command (proportional controller with static gain compensation) and sends SET <command>;
3. the {o1} marker of the table captures this number and publishes it on valueOut[1];
4. valueOut[1] drives the first-order plant, whose output comes back on valueIn[1].

Plotting plant.y shows the temperature reaching the 40 °C setpoint, and sensor.valueOut[1] shows the command changing in steps — one step per dialogue cycle, since the control is only refreshed at the pace of the serial exchanges. This is precisely what this circuit lets you study: the effect of the sampling period imposed by the link speed on the loop dynamics. Lowering baudrate spaces the cycles out and visibly degrades the response.

Components