Just look at the console. It is important to know these values, if not is difficult to understand.
according to the RN2483 manual, the latter refers to an array of values defined in the LoRaWAN specification (here). So one sets according to LoRaWAN definitions, the other sets in dB. However, if you do not know RSSI of received packets, it does not make sense to just play with these values…