The QSB from US Digital, Vancouver, WA, is a quadrature-to-USB adapter that lets you interface standard quadrature encoder signals into a PC USB port for encoder verification. The device is offered in a single-ended (QSB-S) or differential (QSB-D) version. The QSB-M version supports single-ended encoder input, digital I/O, and step/direction motion control output. Each adapter reads quadrature, PWM, and analog encoder signals and has field-upgradeable firmware.
Encoder Interface Device from US Digital
US Digital Corp.