How to interface a Simscape DC motor's 'R' terminal to Simulink outport?

Hi all, I'm trying to model a DC motor on Simscape. An example by MATLAB uses the model below and I am unsure how to interface the R terminal of the motor in Simscape to a Simulink outport. I am unable to figure out what the 'S' block is so I tried using the PS-Simulink converter which is unfortunately not working for me.

Is there any solution to this problem? What is the 'S' block? Thank you.

Answer 1

[Sayan]

Hi Sneha,

The "R" port in the DC motor is a mechanical rotational conserving port. It does not directly measure anything. So you cannot take out this terminal through a PS-Simulink converter directly. However, you can connect it to any sensor to measure rotational motion, linear motion, or position and connect it to a PS-Simulink converter before connecting it to a Simulink outport.

The "S" block is like a subsystem within which there is a sensor sensing the rotational speed of the rotor in rpm, which is then connected to a PS-Simulink converter before connecting to the outport. You can find this example containing a similar "S" block for your reference.

https://www.mathworks.com/help/releases/R2023a/sps/ug/linear-electric-actuator-with-control.html

If you need to take out the "R" terminal crossing a subsystem boundary, you can use Connection ports. You can find more details on them here.

https://www.mathworks.com/help/releases/R2023a/simscape/ref/connectionport.html

You can find more information on the DC motor in the following documentation.

https://www.mathworks.com/help/releases/R2023a/sps/ref/dcmotor.html

Hope this answers the query.