The Zigbee logs show you information about the health of your Zigbee network
- lastHopLqi or Link Quality Index (A) - is an unsigned 8-bit integer ranging from 0 to 255, with the maximum value representing the best possible link quality for delivery of the current packet across the last hop of the incoming route. LQI data is also used by the Zigbee stack to determine connectivity between neighboring nodes, and to select parent devices when joining the network as a ZigBee end device. An LQI below 200 represent links with high error rates, while and LQI of 200 represents approximately an 80% reliability of receiving the data packet intact.
- RSSI or Receiver Signal Strength (B) - is a signed 8-bit integer ranging from approximately -100 to 127, with each value representing the energy level in dBm or decibel-milliwatts at the radio receiver. Indication is the signal strength. Closer to 0 the better as that means less power was used to transmit and is an indication of stronger signal strength. This may be helpful to locate a Zigbee Endpoint device that is dropping off due to interference or weak signal. Since RSSI information does not pertain to any specific link with another device, the measured signal energy at a given frequency can come from any transmitter or device causing interference on that frequency, whether it is another nearby node on the same network, a device from a different PAN (Personal Area Network) on the same channel, or a non-ZigBee, non-802.15.4 source of interference such as a WiFi transmitter or microwave. However, it is important to remember that RSSI information is only between the Endpoint device and the first hop from that device (nearest router / repeater), so this may not necessarily be the hub.
Important note - This troubleshooting and diagnostic data may take up to 20 minutes or longer for devices to check-in, so do not expect to see information reported in the log instantly.