Dear Reader, I want to control the speed of a 4-phase stepper motor using LabVIEW 6i and PCI 6024E card. Hence I am approaching you for help and advice. I want to control the speed of a stepper motor, which is used for rotating the diffraction grating used in the monochromator. Please try and answer a few of my questions: 1. Can I interface the stepper motor directly with the card PCI 6024E, or I need a drive for that purpose? 2. I just want to rotate the stepper motor at a fixed speed, meaning that I don’t want to change the speed of the stepper motor in between, I need a few fixed speeds, what are the problems of controlling the stepper motor using the PCI 6024E cards? 3.Have you been successful in interfacing your stepper motor with the 6025E card?