xbee connecting via coax instead of wireless?

[pigman]

This may sound like a strange question but would it be viable / possible to connect modules in a "daisy chain" style setup over a distance using coax cable instead of wireless between Xbee S1 802.15.4 units? As the unit takes care of the channels and receiving / sending, collision , etc.

Cheers

 

[magvitron]

xbee is meant for RF transmission and there is a communication layer in the protocol. Its might be possible, but there are other good techs such as TWI/I2C , CAN, TCP/IP etc available for it so why bother to adapt it?

 

[pigman]

magvitron, Thanks for your reply. I would adapt it because I already use it in a few projects and I had a thought about daisy chaining S1 xbee's over longer distances using quad shield coax and the antenna connection of each. I like the huge number of addresses you can allocate and use plus my code already utilises this addressing functionality. Would it work robustly if I just hooked all the SMA ports up over coax? would I need some sort of device in between each xbee and the "daisy chain"?

I am communicating Serial over long distances with many "nodes" that all talk to a master, failing xbee what would you recommend that would use Coax as it's means of delivery?

 

[ronsimpson]

You can also use 10-base-T. Has many addresses.
Have you looked at 900mhz xbee. It travels a long distance, with out coax.

 

[kubeek]

You will have trouble with feeding TX of one xbee to RX of another xbee, the RX expects signals say at around -60 to -100dB, while the TX will be around -20dB or more. I doubt that the RX circuitry will be able to cope with such high input level.

 

[misterT]

You will have trouble with feeding TX of one xbee to RX of another xbee, the RX expects signals say at around -60 to -100dB, while the TX will be around -20dB or more. I doubt that the RX circuitry will be able to cope with such high input level.

You can always add attenuators: https://en.wikipedia.org/wiki/Attenuator_(electronics)

 

[pigman]

misterT, interesting. I remember having to ad an attenuator to a connection once when I was doing IT as the G703 link(I think it was a G703) was too strong, close to the exchange...

If this was the case, would I be able to configure some sort of cabled xbee setup with a attenuator between each XBEE and the "network". See the attached. This is exactly what I am trying to achieve, if this would work what would the attenuator need to be ?

IMAGE - Purple line indicates a Quad Shield Coaxial Cable

 

[pigman]

bump, can anyone help here?