Get motor temperature using Rapid

Has anyone found a way to pull temperature data using Rapid from the embedded sensor in an ABB motor? My application caused the motor (MU-300 configured as external axis) to overheat which triggered a program stop. I would like to read the motor temp periodically and adjust the motor rate as the program is running. 

I used TestSignalRead to get torque and speed data but motor temp is not one of the predefined test signals (possible to create a custom signal using this method?). Have also searched through the I/O configuration but unable to locate any analog output signals from the motor. The motor drive has an DI signal for a motor overheat which triggers the controller to halt the program, so I know the signal exists somewhere...


Comments

  • xerim
    xerim
    edited December 2020
    There are no temperature sensors in the robot, only sensors that detect if the motor has overheated. Specifically, Positive Temperate Coefficient thermistors that increase resistance as the temperature increases. 
  • davidmalott
    davidmalott New York
    Is it possible to pull data from these? 
  • I suppose you could use the thermistor as part of a potential divider circuit. If you connect a resistor in parallel with the thermistor, it is possible to divide the voltage between them and "linearize" the response from the thermistor, which you could then use for a temperature reading. There already exists many integrated circuits that do this for you. 
  • davidmalott
    davidmalott New York
    Thanks for the response!