MQTT is a generic protocol, so can you be a little more specific about what device/libs/programmes do (plan) to use?
I changed the behavoir of the m-bus datablock detection.
I recommend to:
Can you give me the manufacturer/medium of the meter? - maybe some specs as well?
first mango is not open-source anymore.
@2 this is a special topic with special questions for special hardware, for special ... , so its better not to expect a vast community.
@3 You can assume ScadaBR as open-source successor of mango.
@4 this means huge effort without pay or benefit for the programmer, go and search for apache commons-math on YouTube, Twitter .... ;-)
But, YOU can change this.
You need a most recently backup of your database B-),
if you haven't any, good luck and try to recover your database:
If you use derby all files under ... see your env.properties
if you use mysql, the mysql database or try to recover the mysql db this would be a MySQL topic...