The Sensor Auto-Detect Service is a background service whose job is to monitor all COM ports not being used by ACQ for new data feeds which may be of interest to the user. It constantly opens each port and iterates through the various setting combinations of baud, parity, flow control, etc in the hopes of finding inputs which look like normal ASCII text.
In the event it discovers valid input it will attempt to determine what type of input it found, which sensor category/type it would belong to and present it via CFE to the user with option of adding it to the active sensor configuration in SCS. Under ideal circumstances you could plug a new sensor into your Digi/Comtrol and in after a bit of time all the data streams coming from that device would be automatically discovered, configured and awaiting your approval from addition to your sensor suite in CFE. This obviously is a nice-to-have feature, it does not prevent you from manually creating any items you want and can be completely ignored or even disabled without impacting the core functionalities of SCS.
If you have a minimally resourced host this may be an optional service you would want to disable to conserve RAM and CPU.
See also: CFE - Auto Sensor Detection