We are running XBee 900HP modules in API mode. Our test group is finding that when we run in our “setup” mode we have more than 5dB stronger signal. Units will run in “setup” mode but fail to connect in operational mode.
We are using Digimesh, but have the hopping disabled (CE=2). Power level is set to 4 (24dBm) in all cases.
The differences between the two modes are as follows:
1) Channel Mask: in setup the mask is always 0xFFFFFFFE00000000 while the channel mask in operational mode is determined by doing a noise scan and selecting the 25 channels with the lowest background noise level.
2)In setup, the sensor nodes send broadcast messages to a host node which replies with a unicast message. In operational mode, the sensor node and the host nodes use unicast messages. 3)In setup mode, the network ID is always 0x7FFF and the preamble byte is 0, while in operational mode the network ID and the preamble byte are derived from our internal serial number for the host node.