XBee Sensor LTH causing CX4 web interface to freeze up

I’ve been using a CX4 with a Smart Plug and an XBee Sensor LT with no problems for some time. Recently I ordered an XBee Sensor LTH to add to the existing network.

The new LTH is causing problems. When it first starts up and associates, it’s fine for a short time. The ASSC light blinks three times then pauses briefly, then continues this way for a short time. As long as this is happening everything is fine.

But within a couple minutes the ASSC light on the new LTH will start to blink continuously. At this point the CX4 web interface becomes non responsive. This includes operations not related to the LTH. This unresponsiveness goes on indefinitely (I’ve waited up to 30 min before taking action).

After, removing batteries from LTH, after a while the CX4 will return to its normal, snappy self. Replace batteries in LTH and the whole set of problems start again.

Ideas? Should I return the LTH for a replacement? Is this an issue with the LTH having newer firmware than the existing nework?

– Prior Existing Equipment –
CX4 overall Firmware Version: (Version 82001536_J1 05/12/2011)

Product Type: X4 Gateway
Firmware Version: 0x2170

Product Type: Smart Plug
Firmware Version: 0x2264

Product Type: XBee /L/T Adapter
Firmware Version: 0x2864

– NEW (problematic) Equipment –
Product Type: XBee /L/T/H Adapter
Firmware Version: 0x2ca7


This is tentative, but I appear to have resolved the issue.

Apparently the XBee Sensor LTH unit shipped with all the pull-up resistors turned off 0x0. In the brief moments after inserting the batteries but before it would exhibit the constant-blink behavior and freeze up the CX4 web interface, I was able to adjust the PR settings. Setting PR back to the correct default of 0x1fff seems to have resolved the issue. At least it has been functioning as expected for 30 min or so.

Of course that was after several hours of troubleshooting and risky firmware updates to the CX4 gateway which ultimately had no bearing on the problem. (At least now I know my CX4 firmware is up to date.)

It is disturbing to me that a mis-configured device can stall out the ConnectPort X4’s web interface. This implies a serious weakness in the ConnectPort X4 that is concerning to me. I hope this is addressed in future updates of the EOS.

Oh, and please ship devices with the proper defaults!