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Joined: Tue Apr 25, 2017 6:03 pm

Datalogging Energy Meter via MODBUS

Tue Apr 25, 2017 6:28 pm

Hello, I have been searching all over the internet and have yet to find the perfect tutorial specific to my application. I am very new to Raspberry Pi coding and this has limited my grasp of the videos and tutorials. I am quick to learn, but need someone to talk to and guide me in the right direction.

Lets start at the top. I work in Energy Efficiency. We have a bunch of stand alone data loggers. (Energy, water, gas, flow, occupancy, etc). Most of these have on board memory. Most of our energy meters have MODBUS and pulse output. The Pulse is usually 1 pulse per kWh. If we were to read modbus we could get each channel Voltage, Amps, PF, kWh. etc.....
Now the question: How do I connect a Raspberry Pi to my energy meter and log all values? I want to build my own application vs purchasing a platform because 1. It's fun. 2. We are looking at other Modbus connected Devices and to have a 3rd party map the registers it not cost effective.

I will be using a Dent Instruments Powerscout 3037. https://shop.dentinstruments.com/collec ... 037-ps3037
Manual with Modbus registers: https://www.dentinstruments.com/hs-fs/h ... 1900520152

I have a Raspberry Pi 2 using a usb converter for comms.https://www.amazon.com/gp/product/B00NK ... UTF8&psc=1

Can anyone help start a step by step process for any new persons?
1. What do I need to download, how do I download,
2. How do I read the data from the meter,
3. How do I log the data from the meter.

Thank you.

Posts: 1
Joined: Thu Jun 01, 2017 1:55 pm

Re: Datalogging Energy Meter via MODBUS

Thu Jun 01, 2017 1:57 pm

Have you made any progress with this? I've got similar situation and I'm trying to figure out how to make this work as well.

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Re: Datalogging Energy Meter via MODBUS

Thu Jun 01, 2017 3:24 pm

I've done a lot of work interfacing Modbus (and other) devices to PC's running HMI & SCADA packages.

For pure monitoring/logging it is fairly safe to write your own logging software, as long as you don't saturate your comm bus, especially for a non-critical home application. This assumes that your Pi is the single master, or you are using Modbus/TCP. If there are other devices doing control that also use the bus, if you cause too much bus utilization, control actions may be delayed, causing potentially serious issues.

Do make sure you have someone experienced, preferably an electrician, for mains/high voltage wiring.

DO NOT try to do control unless you are knowledgeable and experienced.

Generic suggestion:

- google Python Modbus driver
- get the programmer's guide to every piece of gear
- do not expect to get specific free advice for industrial/commercial applications
- roll up your sleeves & dig in!

Specific suggestion:

- hire an experienced consultant

I am actually trying to be helpful - you must remember that experienced consultants have often spent decades learning the ins-and-outs of industrial/commercial applications, and know a lot of pitfalls to watch out for, which will save you a ton of time (which is money) thus are worth the rates they charge.

In >30 years of experience, I have seen a LOT of projects go way over budget and schedule when higher ups decided to save money and do things in-house with inexperienced people, and then have to bring in external consultants to clean up the mess.
http://Mikronauts.com - home of EZasPi, RoboPi, Pi Rtc Dio and Pi Jumper @Mikronauts on Twitter
Advanced Robotics, I/O expansion and prototyping boards for the Raspberry Pi

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Re: Datalogging Energy Meter via MODBUS

Thu Sep 14, 2017 7:32 pm

For the 3) check meterN ;)

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