This product is a USB 2.0 supporting counter unit, which adds the function of counting pulse signals input from external devices through a USB port to a PC. It has four channels of 32-bit up/down counters, allowing external devices such as a rotary encoder and a linear scale to be connected. The pulse signal inputting interface is optocoupler isolated. Compact design, (188.0(W)×78.0(D)×30.5(H)mm), features flexibility in installation. The product can be set on the floor, wall, and inside the console or equipment with the DIN rail. Input interface of pulse signal is opto-coupler isolated input.