National Instruments 7340 PCI User Manual
Page 60
Glossary
© National Instruments Corporation
G-5
H
half-step
mode of a stepper motor—for a two phase motor this is done by alternately
energizing two windings and then only one. In half step mode, alternate
steps are strong and weak but there is significant improvement in low-speed
smoothness over the full-step mode.
hex
hexadecimal
home switch (input)
physical position determined by the mechanical system or designer as the
reference location for system initialization. Frequently, the home position is
also regarded as the zero position in an absolute position frame of reference.
host computer
computer into which the motion control board is plugged
I
I/O
input/output—the transfer of data to and from a computer system involving
communications channels, operator interface devices, and/or motion
control interfaces
ID
identification
in.
inches
index
marker between consecutive encoder revolutions
inverting
polarity of a switch (limit switch, home switch, and so on) in active state.
If these switches are active-low they are said to have inverting polarity.
IRQ
interrupt request
K
k
kilo—the standard metric prefix for 1,000, or 10
3
, used with units of
measure such as volts, hertz, and meters
K
kilo—the prefix for 1,024, or 2
10
, used with B in quantifying data or
computer memory