Explanation: The controller has received communication from the weather station that the weather station's battery is low.
Resolution: Replace the weather station's batteries (two AAA lithium batteries), then sync the SLW5 with the SLHUB within the controller's cabinet. Perform the Blink Test to confirm communcations with the panel. If the 4th Blink is green, you can communicate to the SLHUB inside the controller's cabinet from the designated location. If not you may have to reset the SLW5 hardware and try again.
[See here for a tutorial on replace weather station batteries]
Check out the Blink Test tutorial below.