Support for POW-HVM5.5K-48V needed

[Schekamatik]

Since some days I am trying to get data by RS232-to-TTL module (MAX3232CSE). I am not getting any response from the inverter. I have used this example code: https://github.com/leodesigner/powmr_comm/blob/main/src/main.cpp

The connection to esp32 was done like it is described here: https://github.com/syssi/esphome-smg-ii

Can someone please support me?

Thank you in advance.