xbee pro range problem

Wireless & IoT
1

I have 2 xbee pro ( the 60 mw version) with external antena , and i can´t get a range better than 30 m in open air.

I am using the adafruit adaptors , and the circuit is for remote control (DI close in one side , DO close on the other) , at close range work fine but when is apart more than 30 m the red led go off and don´t work

thanks

2

Check the transmitter output power settings using X-CTU. Perhaps you are running at reduced output.

3

is in the highest output

4

line of sight, 2.4GHz, XBee Pro at highest power, I achieved over a half mile, with one end being the PCB blue chip antenna and the other end being a 5dBi gain omni at 20 ft. elevation.

Both are XBee Pro at max power config?

Interference? Change channels?

Non-line-of-sight?

Proper antennas and correct kind of coax? Or just wire/PCB antennas?

coax or something broken?

5

I get all from sparkfun the antena (2.4GHz Duck Antenna RP-SMA) the adapter cable (Interface Cable RP-SMA to U.FL) and the modules (XBee Pro 60mW U.FL Connection) the adapters are the adafruit adapter kit (http://www.adafruit.com/index.php?main_ … cts_id=126) .

The modules are at ground level , line-of-sight , and setting to high power , and I cant get nore than 30 m

Interference with what ??can you give me a clue?

thanks

6

ptorrado:
I get all from sparkfun the antena (2.4GHz Duck Antenna RP-SMA) the adapter cable (Interface Cable RP-SMA to U.FL) and the modules (XBee Pro 60mW U.FL Connection) the adapters are the adafruit adapter kit (http://www.adafruit.com/index.php?main_ … cts_id=126) .

The modules are at ground level , line-of-sight , and setting to high power , and I cant get nore than 30 m

Interference with what ??can you give me a clue?

thanks

WiFi? Analog 2.4GHz CCTV camera? But it would have to be severe.

try a different channel. If it persists, there’s some other issue.

7

You may have just been in a dead zone, check out this article:

http://www.designnews.com/blog/The_Weir … world_.php

8

The link, above, takes us to a summary of the Fresnel zone effect. It does not apply properly to short path lengths, i.e., as we see used in low power unlicensed 900MHz and 2.4GHz.

In long (say, a mile or more) paths, the Fresnel zone occlusion by buildings and terrain is, like a flashlight’s spreading beam, important if a too-large portion of that beam’s area is blocked. What’s too-large? well, in RF for long links it’s all about the RF Link Budget. That’s a tutorial of its own. Not complicated, just summing gains and losses end to end. The magic part is the budget element called “additional path attenuation from non-line-of-sight”. In most cases, this is well understood and documented from lots of field measurements published by professionals world wide, under vetting by international organizations like ITU and IEEE.

In short range wireless, we do link budgets for non-line-of-sight as estimates, based on things like attenuation from x number of double-layer drywall, some forms of masonry, etc. It can quickly get to be incalculable due to variations in construction materials.

Hope this helps.