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xbee s2 range problem

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I have 2 xb24-z7sit-004(xbee series 2 I think) configured in at serial link mode-one coordinater one router. I am sending low rate serial data at 9600bps. this works fine but the range is terrible! About 10 feet indoors.
I have a laptop with an FTDI serial cable at each end to carry out testing.
I also can connect the router end to a battery powered TI Launchpad(arduino-like) board for further tests.

Each xbee has a Digi A24-hasm-450 aerial atached to its SMA connector.
I ran a link test in xctung. I'd send the scan graph but it seems I can't do attachments here. When the devices are about 4 feet apart the signal is about -68dBm. Double the distance and it goes to about -75dBm. Put the device about 10+ ft away and it drops to -89dBm. Any slight obstacle in the path
also causes further degredation. As a test I tried some old S1 modules
which were never very good at a distance, and got pretty much the same result.

I'm not a beginner at this sort of stuff and I have used other wireless systems from other manufacturers that have worked very well.
Maybe these xbees are just more susceptable to power/RF noise etc.

Any ideas how I can solve this?
asked Nov 6, 2014 in DigiMesh Proprietary Mesh Networking by steeley New to the Community (3 points)

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4 Answers

0 votes
make sure your PL=4 and PM=1. they control power output.

There are international 'low power' versions that can only put out 1/10th as much power; for New Zealand and a few other places I think. You might be dealing with that....

What kind of antenna's are attached? The only way those numbers make any kind of sense would be if no antenna was attached.
answered Nov 6, 2014 by kjensen8 Veteran of the Digi Community (653 points)
0 votes
Thanks for your comments - the aerial I mentioned is this one:

and you are right it does seem as if there is no aerial attached...

The power level settings are not attenuated in the settings.
I think these modules are 1.25 mW (+1 dBm) / 2 mW (+3 dBm) boost mode.

Indoor urban range is quoted as 133 ft (40 m). As spec. sheets are never particularly realistic I would be happy to
get around 20m. I'll look at the aerials tonight and see what the deal is.
answered Nov 7, 2014 by steeley New to the Community (3 points)
ok the aerials seem fine - The devices are on channel 26, so away from regular Wifi. I really cannot see why the range is so bad.
0 votes
Seems the simple answer is to send these Xbees back to the supplier for a refund as they clearly do not work correctly.
answered Nov 10, 2014 by steeley New to the Community (3 points)
0 votes
I also faced the same problem once. But after updating the firmware in both the Xbee devices the problem was solved...
answered Mar 22, 2016 by Gokulkrishnan New to the Community (2 points)