xbee pro 2 and the X-CTU

First time post, so sorry for such a basic question but as everybody i’m trying to learn.

Has anybody got an explination of why on the X-CTU range test you get an almost perfect result if the RSSI box is ticked and if its not it could drop as low as 10%.

Settings are for coordinator and end/router, unchanged apart from the pan ID.

On this simply test I would assume that the Xbee’s would have com problems when not connected to the configurator.

Series 1 vs. series 2 - read up on this.

XBee PRO can have longer range as they have higher Tx power. Non-PRO can do as well with one end or both having a gain antenna, perhaps more gain that the Tx power difference between the two.