Today is...
Monday, June 25, 2018
Welcome to, the global online
community of automation professionals.
Featured Video...
Featured Video
A tutorial introduction to programming using the QuickBuilder Programming Environment.
Our Advertisers
Help keep our servers running...
Patronize our advertisers!
Visit our Post Archive
Low cost modbus meters
Low cost power meter-data acquisition.

Looking to make a low cost power data acquisition system. Wondering if there is a low cost modbus meter for under $100. Just need a basic one that can give the power/energy measurement via modbus. My goal is to create a complete system, meter+datalogger+gateway for <$200.

Any pointers would be great.



I was not able to tell whether you need 3-phase or single-phase and whether this is for your own personal use or to be offered for sale.

But there is a power metering device that already does all of what I understand you are looking for (Metering, Data Logging, Modbus, 100BaseT Gateway).

EIG Shark 200 and Shark 200T...

I don't know the cost, but I'm sure it's more than $200.

The Accuvim II might be another option...


Thanks for the reply. But the Shark and Accuvim are all very very expensive. I have used the Shark100 and some other intelligent meters. All are over $300.

I think there is a need in the market for a very low cost non-utility grade meter. Meaning even if its around 5% accurate its ok. As long as it provides some type of data interface for its contents to be read/written to. Modbus TCP support would be the best.

My design objectives are to bring the cost down to below $200. Is it possible today?

Hi Raj,

I'm glad that u try to do that same thing for an Eco building I'm consulting for a client, so I'm trying to do like your issue. I've used the following: a device smiler to Accuvim, but noname (from China). also I've attached to it a Modbus. I can read the device with their software remotely, but I want to post that online via my own PHP server. then I got download a PHP code module called (Phpmodbus), but I couldn't run it successfully. do u have any success in your project? may be we can exchange ideas?

We do offer such very low cost modbus meter, please feel free to contact us:

By Lowcostsystem on 17 February, 2012 - 2:45 am

You can try with a low-cost Modbus TCP counter device from with any low-cost digital meter with pulse output.

It's easier, and potentially more accurate if you don't care about Real versus Apparent power.

Continental Control Systems has 0 to 0.333VAC touch-safe CTs. Offset that output by 2.5VDC, then amplify to 0 to 5VDC. Now you've got a signal that has plenty of range and can be read directly by any of the small uMCes on the market. Pick a sampling interval that's plenty fast and produce the RMS current. Hard-code the AC line voltage, ignore real versus apparent power, and the as-manufactured cost is under US$100.

Walk in the park.