Switch terminal board H16B relay default controll

[T920919]

can't use AC230v, not need to use voltage.

Just an update on the serial reliability.  I changed from the Host COM1 physical port to a Host USB serial adapter on COM3 and the serial communication is now stable, no longer intermittently losing the last characters. thanks for your help.          I'll try the switch with the Shelly dimmer2 and 2.5 at a later time if needed.