Skip to content

How to use B control energy manager with openHAB

mepi0011 edited this page May 20, 2015 · 1 revision

How to read the wattage and electric energy from B-control energy managers EM100, EM210 and EM300


The B-control energy manager is mostly used in combination with an solar powered system to measure the energy and wattage. B-control released the specification of the JSON and the Modbus interface. With this information, it is possible to get the data and use it with openHAB.

Getting data over JSON

The following instruction use the Exec Binding in combination with a Linux bash script. Additionally the software tools cURL and jq are required. CURL and JQ are included in most Linux distributions. If jq is not available on a particular Linux distribution, you can download it from the project homepage.

The Bash script bcontrol reads the data over the B-Control Energy Manager JSON interface and writes the output to the file bcontrol.out in the path /opt/bcontrol.

Before continuing with this example, create the folder bcontrol in /opt.

Create the file bcontrol and copy the folowing content in to it. Make the file executable.

# Script to get data from B-Control Manager over the JSON interface

# path to write JSON output

# file name for JSON output

# file Name cookie-file (output of curl)

# IP addresse of B-Control manager

# build needed path and links

# get data (JSON) from B-Control Manager
curl -s -b $CookiePath -X GET $JSONLink > $JsonOutput

# check if login is pass
AuthError=$(/usr/local/bin/jq 'has("authentication")' $JsonOutput)

if [ $AuthError  = "true" ]
  echo "Login Error: Login will be repeat!"
  curl -s --cookie-jar $CookiePath $LoginLink > /dev/null
  curl -s -b $CookiePath --cookie-jar $CookiePath -d "login=<serial-no>&password=<password>&save_login=1" $LoginLink > /dev/null
  curl -s -b $CookiePath -X GET $JSONLink > $JsonOutput

# Rueckgabe des gewuenschten Wertes
case "$1" in
	CurrentConsumption)	echo $(/usr/local/bin/jq '.["1-0:1.4.0*255"]' $JsonOutput);;
	CurrentFeeding)		echo $(/usr/local/bin/jq '.["1-0:2.4.0*255"]' $JsonOutput);;
	TotalConsumption)	echo $(/usr/local/bin/jq '.["1-0:1.8.0*255"]' $JsonOutput);;
	TotalFeeding)		echo $(/usr/local/bin/jq '.["1-0:2.8.0*255"]' $JsonOutput);;
	*)			echo "unknown parameter!"
				exit 1;;

exit 0

Replace / with the USER name (default is this the serial number of the B-control manager), / with the password of the B-control manager (if no password has been set, leave it blank) and change the IP Address of the B-control manager.

Now you can test the script without openHAB with the command:

/opt/TQManager/bcontrol TotalConsumption

If everything is okay, you will get a valid value. You are now able to use the scrit in openHAB.

To use the script in openHAB, copy the Exec Binding to the folder called addons. In your items file you can define the following Number items.

Number BCM_consumption_wattage		"current wattage consumption [%.1f W]"	{exec="<[/opt/bcontrol/bcontrol@@CurrentConsumption:5000:REGEX((.*?))]"}
Number BCM_feeding_wattage		    "current feeding wattage [%.1f W]"	    {exec="<[/opt/bcontrol/bcontrol@@CurrentFeeding:5000:REGEX((.*?))]"}
Number BCM_energy_value_consumption	"energy value consumption [%.1f Wh]"	{exec="<[/opt/bcontrol/bcontrol@@TotalConsumption:10000:REGEX((.*?))]"}
Number BCM_energy_value_feeding		"energy value feeding [%.1f Wh]"	    {exec="<[/opt/bcontrol/bcontrol@@TotalFeeding:10000:REGEX((.*?))]"}

feature overview


Setup intro

Linux and OS X





User Interfaces



(link to openHAB forum)



Application Integration



A good source of inspiration and tips from users gathered over the years. Be aware that things may have changed since they were written and some examples might not work correctly.

Please update the wiki if you do come across any out of date information.

Binding configurations

Use case examples

Item definition examples

Sitemap definition examples

Collections of Rules on a single page

Single Rules


Syntax highlighting for external editors

Release Notes

Clone this wiki locally
You can’t perform that action at this time.