Without the pullup, there does not appear to be any data on the smart meter's P1 port. The documentation doesn't mention that it is open-collector output and even says the output voltage is >4V for `0`. I had to buy a €15 adapter cable and disassemble it to learn this, so I hope this information helps someone else.
Without the pullup, there does not appear to be any data on the smart meter's P1 port. The documentation doesn't mention that it is open-collector output and even says the output voltage is >4V for `0`. I had to buy a €15 adapter cable and disassemble it to learn this, so I hope this information helps someone else.