Disclosed herein are system, apparatus, article of manufacture, method and/or computer program product embodiments, and/or combinations and sub-combinations thereof, for automatically determining the functionality and capabilities of electronic components. Some embodiments operate by transmitting a command to the display device in question (sometimes called the device under test—DUT—herein) and monitoring the device. Then, it is determined whether an action by the display device was one of a set of proper responses to the command. If the action was proper, then it is determined that the display device supports the command set associated with the command. The command set may be the Consumer Electronics Control (CEC) set, although this disclosure is not limited to that example.