RSSI Unavailable (127) when reading advertising data with BlueNRG-1

[GMore.1]

Hello all,

I have currently set up a BlueNRG-1 as a passive scanner for a few Eddystone beacons. When acquiring the RSSI data from the beacon's received advertising packet using HCI_Read_RSSI, we are often (70% time) reading the decimal value "127".

According to UM1755, Table 115, this indicates a "RSSI not available" occurence. What could be causing the measure to become unavailable? Is the availability related to the received singal strength?

Thanks in advance,

GSLM