parameters from EM50

I want to readout and sent every 5 minutes or so the different parameters from an EM50. There should be 1 voltage and 2 power measurements that interests me.
I have a script running and sending info to an mqtt however, I don't know how to get those above mentioned data into variables that I can sent over with mqtt.
What are the 'build-in' names and how to get them?
I've searched and searched but most likely looking into the wrong places, it can't be that dificult I would think.