plug in terminal block is used to achieve an electrical connection accessories, is divided on the scope of the connector industry. With the increasingly mini usb connector level of industrial automation and industrial control requirements become more stringent, accurate, plug in terminal block dosage gradually rising. With the development of the electronics industry, the use of the terminal more and more, and more and more types. Currently the most telephone jack used in addition to the PCB terminal, there are hardware terminals, screw terminals, spring terminals, etc., in the power industry have a special terminal block, terminal box, above all terminals, monolayer, bilayer , current, voltage, ordinary, and the like can be broken.