What indication does a sensor supervisory trouble suggest?

A sensor supervisory trouble indicates that the sensor is not sending expected signals. This condition is typically identified when a monitoring system detects that a sensor hasn't communicated its status within a designated time frame, which suggests a potential issue with the sensor's functionality or connection to the control panel.

In a properly functioning system, sensors send regular signals to the control panel, confirming their operational status. If no signal is received, it raises an alert, prompting a need for investigation. This situation could arise from factors such as a wiring issue, battery failure, or sensor malfunction, which means the sensor is not actively communicating as it should.

The other options relate to normal or expected conditions for the sensor. For example, the notion that a sensor could be working correctly would not align with the definition of a supervisory trouble, as it specifically implies a communication failure. Similarly, frequent adjustments or being ready for activation do not encompass the underlying issue represented by the supervisory trouble, which is primarily centered on the lack of expected signals from the sensor.