XBee SE association question

Question

Hi all,

I have been playing around with an XBee Pro with SE firmware on it using XCTU. I've been trying to get it to act as an IPD and associate itself with a Metering device that I control, but there seems to be a few issues.

I have a packet sniffer running and see that the XBee IPD device tries to connect with the Meter, and actually gets pretty far. The flow is something like this:

IPD: Beacon Request
Meter: Beacon
IPD: Association Request
Meter: Association Response
Meter: Transport Key
IPD: Device Announce
Meter: Device Announce
... random IPD: Data Request messages (MAC)...
IPD: Match Descriptor Request (ZDP)
Meter: Match Descriptor Response (ZDP) <- get an 'Explicit RX Indicator' on XCTU for this
Meter: Acknowledgement (APS)
IPD: Acknowledgement (APS)
... repeat entire process...

It seems like after awhile, the XBee IPD gives up? and decides to look for another network to join. I'm not sure why, since the Meter looks like it has already accepted it...

Anybody know what is going on? I have no idea, sadly

Answer 1

Are test certificates installed on both nodes (meter and XBee)? In Smart Energy matching certificates are required (test or production). Is an installation code or link key being used to join the XBee to the meter?

Since the meter is acting as the coordinator and forms the network, you would need to enter the XBee EUI 64 address and installation code/link key on the meter so it allows joining.

Comments

I have full control over the Metering device which is how I can get the XBee to connect to it. I'm using pre-configured link keys and tell the Meter to allow joining for about a minute, during which the process I described above happens (until it disallows joining again)

I thought the same thing as you did with respect to the certificate, so I tried setting EO on the XBee to 0 to disable it. Looking at the packet sniffer, it doesn't seem like there was any need for authentication, nor were there any unanswered packets from the XBee. The XBee just decided to re-connect for some reason.

I've also tried sending 0x11 packets through the API, but the XBee doesn't process them at all either. No response from the XBee, and no packets sent out that would correspond to the request. It seems weird, considering it definitely has joined the network.

Answer 2

It seems like after awhile, the XBee IPD gives up?

Comments

Yes, after 3 tries or so it stops trying to connect. Although this may be because the Meter stops allowing joins after 90 seconds.

Answer 3

Are you using Router or End Device firmware? What firmware version? S2B or S2C? Does the XBee still send a Match Descriptor Request even with EO=0? What clusters is it looking for with the Match Descriptor Request and what is the meter's response? Do you have an over-the-air trace of the entire sequence?

Answer 4

I have a packet sniffer running and see that the XBee IPD device tries to connect with the Meter, and actually gets pretty far. The flow is something like this:





___________
kaleem

Comments

If you have a trace can send it to the address listed in my profile since I don't think files can be attached here. Make sure to include the NWK key or pre-configured link key.