Signal acquisition controller

The invention discloses a signal acquisition controller, which quickly judges the overcurrent state of a three-phase alternating current. The signal acquisition controller comprises an input/output board and a central processing unit board, wherein the input/output board is used for receiving an alternating-current signal acquired by peripheral equipment on the three-phase alternating current, and conditioning the alternating-current signal to acquire an alternating-current conditioning signal, and is also used for executing the circuit protection action according to a protective signal sent by the central processing unit board; the central processing unit board is used for receiving a judging threshold value inputted by a user and judging whether the three-phase alternating current is in the overcurrent state or not according to the judging threshold value and the alternating-current conditioning signal; if the three-phase alternating current is in the overcurrent state, the central processing unit board generates the protective signal and judges the protective signal is a quick protective signal or not; and if the protective signal is the quick protective signal, the protective signal is sent to the input/output board, otherwise the protective signal is sent to the peripheral equipment. The method and the device acquire and judge the alternating current directly, shorten the signal acquisition time and the protective time during overcurrent.