As SPDT Relays are much more new to me and using it 4-20mA current loop sensors are much more thinking process as I am new to area
I want these SPDT relay to control the alarm processing
please suggest me as I am using 4-20mA sensor with 4-20mA current loop receiver and if any of the 4-20mA sensor readings increase from set value(like if set value is 28 degree Celsius) then the corresponding alarm relay will be activated as I am working for project so PLC is much more costly I wanted to know can I make this circuit or use any kind of hardware to make the alarm system manual(without coding)?
or I have to use open source circuit boards (like Arduino , Raspberry Pi)
Please help me out in schematic if we can make it manually
