Hi,

We all know that various electronic devices use modbus protocol for communicating electronic devices. I just want to know whether modbus protocol is same for every kind of water meter or electric meter or for all meters.

I am a computer engineer and I have no idea about these electronic devices. I have been assigned a task to read data (readings) from every kind of electronic meter (like water meter or gas meter or electricity meter) using java application. So, I just want to know whether all devices use same type of modbus protocol or there is any other story.

Please give me the direction

Thank you

 

The Modbus protocol is the same, however baudrate, parity, physical layer (RS232/485) etc will be different and usually one can select what baudrate and slave ID that the Modbus slave should use.

Furthermore, the data mapping will also be different for all devices.
Reading register 1 from product A may contain flow, while reading the same register from product B may contain temperature...

//Patrick L
HMS

 

Hi,

Many use DNP3.

Good luck,

Mark
http://www.peakhmi.com/

 

Assume every BRAND of meter has a different Modbus layout - plus there is NO easy way to 'browse' or read the meter to determine it's type. Utility meters tend to have under-powered CPUs, so many implement the barest-bone data map they can. If the meter has 6 words of data, reading 7 words will fail, and so on.

Shockingly, even within the same company, it may not be possible to know which meter you are talking to dynamically - someone may have to manually configure your tool to know which meter is where, thus telling you what registers to read and how to interpret the values returned.

 

Thanks for the reply Can you please tell me various protocols (except Modbus) which would be getting used for meters like water meter, electric meter or gas meter. Or from where I can get the list?

 

I work on a pretty extensive setup similar to the one you are describing. We have an entire network dedicated to these systems well over a million points of data.

Modbus is the protocol you want because modbus is modbus no matter the manufacturer. As readers have told you knowing registers and baudrate are going to very. This is where Ethernet Gateways and an OPC server help out.

Pretty much all of my modbus devices tie into either an EGX100 or EGX300 (ethernet gateways made by square D) these turn the RS485/232 signals into a modbus ethernet signal. Speeds things up.

Now you need to setup an OPC server. This ties everything together into one type of data. You basically use an address similar to accessing a file from another server. A couple of OPC server are these TopServer, Matrikon, Iconics are to just name a few. I use TopServer currently because that is what we have licenses for and it works, but I like Matrikon and Iconics support better.

This is the point where you would tie in your Java app. The Java app would just be pulling values from the OPC server. At least this is how I would see your project functioning at its best.

If you have any other questions please feel free to post and will do my best to answer.

 

My company works a lot with large utilities handling demand-response. Unfortunately, the product class of "Utility Meter", be they water, gas or electricity, are still pretty much mired in both proprietary hardware and proprietary protocols.

So one can buy (for example) an Itron meter for under $100, but you'll need Itron tools to talk to it. This is because your average power utility who buys 100,000 meters tends to cluster them under neighborhood/area controllers - so they do NOT want to talk to 100,000 meters, but perhaps to 300 neighborhood/area controllers. So they pay $5K or even $10K for a fancy neighborhood/area controllers which reads in some hundreds of proprietary meters via wireless & may speak Modbus, DNP or IEC 61850 upstream to the SCADA host.

MANY companies also make meters which speak Modbus, yet the price easily jumps to from $300 to $1000 each.

Want DNP3 direct in the meter? Then the price hovers near the upper end of the Modbus meters.

 

Here is an example of modbus mapping in a power meter: http://www.icpdas-usa.com/documents/PM-213x_User's_Manual_V1.5.pdf , see page 18.

 

Hi Kshitiz,

There are many electric meters that feature modbus capability that you can read via your java app. Water meters and gas meters... not so many choices.

My company does manufacture a bridge/gateway device, the 'EtherMeter', that converts water and gas meter readings (both encoder-based and pulse-based) into Modbus, DF1, and EtherNet/IP. Supported media include Ethernet, RS-232, and RS-485.

It will also give you the added benefit of all your water and gas meters having a common Modbus memory-mapping interface, even if they are a collection of varied makes & models.

Hope this helps!

Jim Mimlitz,
SCADAmetrics

 

I've looked around and found http://www.modbusdriver.com/ I also found a very simple modbus driver for Java. I was wondering if there was a standard open modbus driver for Java or C that has many tutorials supporting it?