KC868-A4 Serial Ports and Scl Sda ? and Voltage range of 4-20mA ports

[admin]

1. KC868-A4 have a RS232 port, if you want to communication with Nextion screen by serial, you just need to add RS232-TTL level adapter. Nextion screen i think is 3.3V level.
2. use DC12V or 24V sensor all no problem, because you can connect with 4-20mA teminal, it just according to current, not by voltage. use DC24v will be let the cable long distance.