Idle Current Reduction:
   
    A stepping motor driver feature that reduces the phase current to the motor when no motor motion (idle) is commanded for a specified period of time. This reduces motor heating and allows high machine throughput to be obtained from a given motor.
   
    IEEE-488
   
    A digital data communications standard popular in instrumentation electronics. This parallel interface is also known as GPIB, or General Purpose Interface Bus.
   
    IGBT:
   
    Insulated Gate Bipolar Transistor. Used as the output power devices in PWM drives. IGBT's are good for high voltage and high current drives.
   
    Incremental Motion:
   
    A motion control term that describes a device that produces one step of motion for each step command (usually a pulse) received.
   
    Incremental Programming:
   
    A coordinate system where positions or distances are specified relative to the current position.
   
    Indexer:
   
    Electronics which convert high level motion commands from a host computer, programmable controller, or operator panel into step and direction pulse streams for use by the stepping motor driver.See PMC
   
   
    Inductance:
   
    The tendency of a motor coil to store energy in a magnetic field. High speed stepping motor performance is inversely proportional to motor inductance.
   
   
    Inertia:
   
    A measure of an objects resistance to a change in velocity. The larger an objects inertia, the larger the torque that is required to accelerate or decelerate it. Inertia is a function of an objects mass and its shape. For the most efficient operation, the system-coupling ratio should be selected so that the reflected inertia of the load is equal to or no greater than 10 times the rotor inertia of the stepper motor.
   
   
    Inertia (Reflected):
   
    Inertia as seen by the stepper motor when driving through a speed change, reducer or gear train.
   
    Interpolate:
   
    To calculate values between two intermediate points. Linear interpolation connects the dots with straight lines with no smoothness. 3rd order interpolation uses smooth curves between points.
   
    Interpolator:
   
    A subroutine that interpolates. AMC drives use 3rd order interpolation positioning. This reduces network traffic by allowing the controller to send fewer position points but still keep smoothness and accuracy between points.
   
   
   
   
    Inertial Match:
   
    For most efficient operation, the system coupling ratio should be selected so that the reflected inertia of the load is equal to the rotor inertia of the motor.
   
    I/O:
   
    The reception and transmission of information between control devices. In modern control systems, I / O has two distinct forms: switches, relays, etc. which are in either an on or off state, or analog signals that are continuous in nature such as speed, temperature, flow, etc.
   
   
    Kd:
   
    Common abbreviation for derivative gain.
   
    Ki:
   
    Common abbreviation for Integral gain.
   
    Kp:
   
    Common abbreviation for proportional gain.