XBee 900 XR broadcast problem

XBee & XBee Gateway
1

I have a design that is working pretty well. The application is remote control, so I’m trying to keep things as close to real time as possible. I use unicast messages, and I observed that when I got to the edge of range, there would be a burst of messages. I realized that these were retries, but since in this case it is already stale data, I set the RR parameter to 0. This made the system faster to resync when coming back in range, but it seems to have an unexpected side effect. The pairing routine is the one case where I use broadcast messages, and after setting RR to 0, the broadcast messages never are received. The RSSI on other radios don’t even light up when the broadcast message is supposed to be sending. Setting the RR parameter back to the default fixed my broadcast error. Shouldn’t broadcast messages and the RR parameter be unrelated?

Radio: XB-9XR-DMUS-001

Parameters: TO: 0x40, RR: 0, C8: 4, CE: 2,

Thanks!

2

Since you are using a Non routing module and TO 0x40, setting RR to 0 turns off all retries and multi-transmits.

3

Thanks for the reply.

Is there a way for me to turn off retries for unicast messages and still be able to transmit broadcast messages?

4

If you are using API mode, you can send a local AT command first to set RR to 0 for unicast packet. Then when you want to send broadcast, set it to 1.

5

If I leave RR set to 1, will that mean that unicast messages will be retried only one time, and broadcast messages will be transmitted?

6

@mvut If I leave RR set to 1, will that mean that unicast messages will be retried only one time, and broadcast messages will be transmitted?

7

Yes, the packet will be retried under a unicast packet. For a broadcast, it will be sent twice.