Abstract:
The technology of twenty century covers the side of safety and security system field in a very compressing steps, because the development was so fast.
In this research the electronic mechanism used in certain places; the application used was simply detectors "sensors" especially of heat and gas.
The sensors of heat and gas depend mainly on sensitivity of them; and so the effect reflects on the circuit.
The best choice was PLC testing; the signal found was treated using ladder diagram "programming language".
When output is found the devices directly gives "buzzer / lamp" signal
