zigbee wireless network

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ccesena
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Joined: Sun May 19, 2013 12:25 pm

zigbee wireless network

Post by ccesena » Mon Jul 29, 2013 6:27 pm

Hi,
I have 16 meters in a RS-485 network. The link between two of the branches is being done with the EKM 485BEE adapter, the question is can I add two wireless branch more to the one I am now running?
Thank You

Jameson
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Re: zigbee wireless network

Post by Jameson » Tue Jul 30, 2013 10:37 am

Hello ccesena,

Yes, you can have many more 485Bees on your RS485 network (I am not sure of the upper limit to be honest, but we have worked with networks that have 20 485Bees.) Each 485Bee in the network acts as a node in the mesh network. Each node extends the network and can be either the target or a hopping point for the RS485 signal. If you are having trouble with communications between 2 of the 485Bees because they are out of range of each other, you can add a 485Bee between them to bounce the signal.

Each 485Bee can have up to 256 meters connected to it.

So, yes you should easily be able to add a few more branches to your 485Bee network. The 485Bees act as a replacement for the wired link anywhere that it is too difficult or costly to run wires.

Please see this communication diagram for your reference: http://documents.ekmmetering.com/EKM-Me ... 485Bee.png

If you have any questions, please let us know.

Thanks,
Jameson
EKM METERING
http://www.ekmmetering.com
831.425.7371

pvanroos
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Joined: Wed May 28, 2014 8:52 am

Re: zigbee wireless network

Post by pvanroos » Tue Sep 09, 2014 12:20 pm

Jameson,

Have you guys tried powering the EKM 485Bee with a solar panel that provides 6 V DC?

-Paul

Jameson
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Re: zigbee wireless network

Post by Jameson » Tue Sep 09, 2014 6:00 pm

Yes, we have actually. It worked pretty well.

I prefer to power the 485Bees with 12VDC, but at 6 VDC it worked.

The solar panel we use was 3 watts 5.87 volts, connected to a small Lithium Ion Batter Pack. This was a long time ago, so I don't remember much, but I think it worked pretty well. I cant remember how many cloudy days in a row it would make it through. I might get a bit bigger solar panel and bigger battery next time.

I would think you would definitely want a battery in the system (to buffer the voltage if nothing else)

Hope this helps,
Jameson
EKM METERING
http://www.ekmmetering.com
831.425.7371

pvanroos
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Joined: Wed May 28, 2014 8:52 am

Re: zigbee wireless network

Post by pvanroos » Wed Sep 10, 2014 12:32 pm

Jameson,

Thanks. That gives me confidence. One other question: How often does the Zigbee device send signals and how much power does it draw in say, a given day?

Pardon me if this is obvious from specs. Perhaps I missed it.



-Paul

Jameson
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Re: zigbee wireless network

Post by Jameson » Wed Sep 10, 2014 4:38 pm

The 485Bee draws less than 50mA at 12VDC (very roughly 0.6 watts). We have had a tiny 9VDC battery (the rectangular kind that goes in a smoke detector) power an 485Bee for about 8 to 12 hours. So a larger battery would/should last a few days/weeks (especially if you are going to augment with solar)

If you are really interested in optimizing this, it is possible to put the radio into a sleep mode using AT commands (we have not done this ourselves). We use 900 mHz Digimesh xBee radios that are made by Digi, if you want to look for more info.

The radios are always connected to each other, but we only transfer meter data as often as you make a meter read. In the case of the Dash software this is as often as once per second, or in the case of the EKM Push connected to just 1 meter it is once per minute (for free).

Here is the 485Bee spec sheet just in case: http://documents.ekmmetering.com/485Bee-Spec-Sheet.pdf

Hope this helps.
Jameson
EKM METERING
http://www.ekmmetering.com
831.425.7371

pvanroos
Posts: 11
Joined: Wed May 28, 2014 8:52 am

Re: zigbee wireless network

Post by pvanroos » Thu Sep 11, 2014 9:00 am

Perfect! Thanks again.

-Paul

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