Switch device and wiring structure therefor

A switch device comprising:

• a main body comprising a sensor disposed therein for producing an electrical signal in response to a predetermined air pressure applied to said sensor and a terminal connected to said sensor through which the electrical signal is output;
• a setting section detachably mounted on said main body, said setting section comprising a control unit and display means, said control unit connected to the terminal for receiving the electrical signal and externally outputting a detection signal through a signal line detachably connected to the control unit, said detection signal comprising an on-state signal and an off-state signal depending on the electrical signal outputted by said sensor, and said display means displaying thereon detection signal determining conditions which have been set in advance;
• wherein said setting section further comprises a control module, said control module having said display means therein, and wherein said control module is detachably mounted on said control unit.