The SMC series channel switcher ( Be called SMC)is one product that can solve mutual transform of multi-serial communication mode and multi-switch mode transform among the double-channel, according to the practical application need in signal acquisition field of current electric power, telecommunication and other communication network systems. SMC uses the one-chip computer control, has multi-device''''''''''''''''s double-channel switch mode, as well as serial transformation between the input channel and the output channel. It has quick switch speed, light disturbing, high transmission efficiency, adjustable time delaying, faultless data transmission, and provides completely "transparent" full duplex channel for the user. SMC has the exchange function of RS232/485/422 serial among the input and output port , unifies the "direct""cross" "one to two" , "auto-judgment" and so on many kinds of channels switch modes among two input ports and two output ports, may nimbly apply to each automatic system''''''''''''''''s data acquisition and transformation scene. For example, on the occasion that need the active-standby channel redundancy, or there is only one data in the device channel, while the acquisition system needs two routes same data, or there are many device channels, while the serial sport modes are different, SMC also can combine the functions to achieve the user''''''''''''''''s request. Therefore when it needed, the signal gaining function between the input and output port may serve as the signal gaining lengthener in the long-distance transmission channel.