Pin D2 is LOW and pins D3 and D4 are HIGH.
A short call with back light on for under 20 seconds the socket ON for 60 minutes. If you decide that you want to cancel, a short number of rings that keeps the back light ON for less tan 20 seconds will turn the socket OFF.
See Mode 1 for explanation of backlight timings.
This Mode is ideal for turning ON the socket with an automated text. See below on AUTOMATIC OPERATION OF SOCKETS.