The scenario
A smart irrigation system uses a rain sensor to prevent watering when it rains. Two zone valves are controlled manually via push buttons with a seal-in circuit, but only if the system is enabled and the rain sensor is dry.
What is in this drawing
Read the decisions behind it.
01
Rain sensor input is normally closed (XIO)
02
System enable switch allows overall control
03
Seal-in circuit for each zone valve using parallel branch to maintain after start button release
When designing irrigation control logic for home automation systems with safety interlocks.
More like this