Script to read information from Landis+Gyr Ultraheat (UH50, T550)

With this script you can read a telegram from a Landis&Gyr Ultraheat 2WR5 'Stadsverwarming' meter. Most likely this also works for Ultraheat UH50 (T550).

This script sends the MJ and m3 values to Domoticz on the given IDX.

This script uses a optical probe (IEC 62056-21) on an USB port to read the telegrams from the meter.

Add a custom sensor with MJ and m3 Y-axis settings (Add through dummy sensor hardware). This is best done by adding a 'Counter' dummy sensor in Domoticz. Edit the device and select the 'Counter' type. You will now also get 2 fields for 'Value quantity' and 'Value units'. A same type of sensor can be added for the M3 value.

The script will send the values to Domoticz in MJ (1GJ = 1000MJ) and liters (not m3). This is to make the graphs in Domoticz better. A usage of 0,11GJ compared with 0,12GJ will be on a very small scale, whereas 110MJ and 120MJ will give a better scale.

It is said that every readout of the Ultraheat is shortening the livespan of the battery by 15 minutes. Usually these batteries last for many years, but please make sure you don't read the values too often. There is little added value in fetching the data very frequently. I fetch it a few times a day to get an idea of the heat usage over a few parts of the day (every 6 hours).

• An optical probe (IEC 62056-21 standard) to place on the meter, for example: http://wiki.volkszaehler.org/hardware/controllers/ir-schreib-lesekopf-usb-ausgang
• Python3
• A home automation application like Domoticz of Home Assistant

Original script from Magnat in https://gathering.tweakers.net/forum/list_messages/1535019