RED LED Ring Blinking: RS485 Photosynthetically Active Radiation (PAR) Sensor (400-700nm)

I have the Dfrobot par sensor hat utilize rs485. I’ve wired it and successfully used it. the other day after flashing firmware in my device that controls it, but without uploading the files to the device, it sat idle not polling the sensor. After some time this Red LED ring light the circles the entire bottom started flashing and it turning off. 
 

there is no LED information in the documentation, wiki, or anywhwre online I can find. Clearly these have status LEDs that are very prominent, what’s the point if the user doesn’t even know what it means or why it’s happening. 
 

can anyone shed some light? Is the red LED flashing from idle activity? What else might it be if all my voltages are correct at all points with multimeter and sensor can be polled successfully? Are there other colors? Are these able to be utilizex for quick status updates from afar visually or why include them at all and have them turn on if we don’t get to know why?

thanks for any help.