Help needed:
I want to be able to record 250 plus electric readings at source over a 2 acre site, and would like to take this all back to the office computer and then to the cloud. Has anyone got any ideas, as the Wi-Fi will not reach all areas. Please help with a reasonable, cost effective, solution.
I think we need a little more detail, because there are so many factors that might influence your choice of solution:
Where are you in the world?
What quantities do you want to measure, have you got anything in mind as to how you are intending to make those measurements, and how often?
What area does the site cover - I know you say 2 acres, but what are the linear dimensions? i.e. assuming that radio is used, how far must it reach? What is the nature of the site, green fields, wooden buildings, brick/concrete/stone buildings? How many separate locations, and how many readings from each?
Is mains power available everywhere?
How do you intend to get the measurements back to the office, and how often?
ok the only thing we need to measure is electrical consumption, there is electric at every point around the yard but we have boats everywhere which can interfere with transmitting and don’t have cat 5 in either here is a link to a map of the yard boat yard thanks for offering to help iam quite happy to call you to dicuss the project Robert
Would these do the job? Seem to create a mesh network. http://crownstone.rocks/products/built-in-crownstone Came up in a different discussion.
Would I be right to think that you want power and energy readings so that you can charge the boat owners for the energy they buy from you?
How often do you want that information recorded? How do you intend to get the measurements back to the office, and how often?
I am still not clear regarding exactly what you want to do, but these are my thoughts so far:
The emonTx would not be suitable for you for several reasons, but it (or parts of it) could form the starting point for a custom design. The alternative might be a dedicated energy monitoring i.c. with a microprocessor handling the interface between it and a low-power radio. For that, the RFM69CW is probably more suited as it works at a lower frequency than Wi-Fi.
The radio protocol we use (JeeLib) is not suitable as it stands, being capable of handling only 31 outstations (“nodes”), so that too would need customizing, or a different protocol chosen. LowPowerLabs can handle 255 nodes. With 250 outstations, you probably need a radio protocol whereby the base station interrogates each outstation in turn in order to obtain the data.
You could probably use emonCMS if you require graphical interpretation of the data when it has been collected, but depending on what you use the data for, again a custom database might be preferable or necessary.
A custom hardware design would have a high initial cost, but with >250 units to be manufactured, that would be balanced by the advantages of having exactly what you need and nothing more in each outstation.
[Thanks, Brian, I knew I’d seen something recently that might do the job, but 250 at €90 each, they are hardly “reasonable, cost-effective” - though no doubt a significant quantity discount would be negotiable.]
thank you Brian and Robert ive sent them an email the Mesh network with 20 to 70 meter range may be the answer i will keep you in the loop
How will the readings be done:
1: Are there already an energy meter at each location?
2: If so does support pulse counting.(is there an S0 output)
3: If not is a current sensor like this 100A max clip-on current sensor CT - Shop | OpenEnergyMonitor an option
Both JeeLibs and LowPowerLabs supports 250 network groups with 31/255 nodes each, so there are plenty of endpoints available
Then what? He’ll need an emonTx or the equivalent × 250. That’s why I suggest a custom-designed unit, which could be more cost-effective.
Hi Paul,
I’m using emoncms in an industrial environment to monitor and visualise the energy flow in a factory. As measurement devices, we are using are from socomec. Here you can use RF or Modbus (1,2 km max. distance) conections between measuring devices and data logger / gateways.
I our case, we use B30 http://www.socomec.com/wireless-metering-measurement_en.html as sensors and http://www.socomec.com/communication-interfaces_en.html as gateways. Afaik you can connect 32 BXX to one gateway and up to 4 current transformer to one B30. The gateways generates a csv file (every 10 min.), which transfers the data to emoncms and have an integrated webserver which shows most values.