Some older U60s had the wrong LED labels. The correct U60 LED functionality is described below and in the SmartServer IoT User's Guide.
Three LEDs are located in the center of the U60 enclosure:
1. The yellow Service LED on the left (labelled Link or Service), provides a visual indication of the network status of the U60.
2. The RX LED in the middle flashes green when data is received from the network.
3. The TX LED on the right flashes green when data is transmitted onto the network.