A portable, fast and accurate optical beam positioning system having a USB2.0 interface. The system is based on a 24 bit A/D electronics box, powered via the USB2.0 port. It offers simultaneous operation of one or two PSD's in one system. The PSD's are Lateral Effect type or Four-Quadrant type. There is a variety of sensor head types and sizes. The update rate is up to 150 Hz when using a 500 Hz digital filter. The spectral range is 350-1100nm. Operation systems supported are Windows XP, Vista, 7, 8, 10 - both 32 and 64 bits.