There are 9 core LEDs on the ZumLink products as listed below:

• CD - Carrier Detect / RF Link . Bi-colored LED.  (Red / Green)
  • Solid Green when RF link. 
    • Steady GREEN when receive sensitivity margins are > 20db
    • Flashes RED when receive sensitivity margins are < 20db
  • Blinking Amber when saving configuration or applying firmware update.
  • Solid Red when NO RF Link
  • Alternate Blinking Red/Green When Transmitting/Receiving RF Data.
• TX - RF Transmit. tri-colored LED (Red / Green / Amber)
  • Blinking Amber/Red when saving configuration or applying firmware update.
  • Blinking Green when Transmitting data over RF
• RX/CTS - RF Receive, tri-colored LED  (Red / Green)
  • Blinking Green when receiving data over RF.
• COM1 Left - Blinking when Transmitting Serial Data on COM1 (Green LED)
• COM1 Right - Blinking when Receiving Serial Data on COM1 (Green LED)
• COM2 Left - Blinking when Transmitting Serial Data on COM2 Port (Green LED)
• COM2 Right - Blinking when Receiving Serial Data on COM2 Port (Green LED)
• Ethernet Left - Green LED when there isPower to the Ethernet port (Green LED)
• Ethernet Right - Blinking green LED show Ethernet activity (either sending or receiving) (Green LED)

Note 1: Left and Right in this case are as you are looking at the ports.

Normal Operation

The first 3 LEDs are related to the Radio and they will behave differently for different configurations. The following shows the different configurations and the respective LED behaviors during normal operation.