Manual

Introduction 1-3
Microstep Size, Resolution, and Maximum Travel
The Automove X-Y tables are shipped with 1.8-degree stepping motors. This means that the
motors have 200 full steps per revolution. (There are 50 physical poles on the rotor; four full
steps cause a pole to rotate to the position formerly occupied by its neighbor.) By default the
Automove System divides each full step into eight microsteps, giving 1600 microsteps per
revolution. Each microstep on an Automove table produces nominally 0.001 inch of
carriage travel.
The System allows a total travel of 32766 microsteps in each axis, or about 32 inches in the
default configuration. If this produces too little overall travel for your application, or if eight
microsteps per full step is too coarse, you can change the size of a microstep via the RE
("Resolution") command. A microstep can be as large as one full step, or as small as one
thirty-second of a full step. This gives a range of 200 through 6400 microsteps per
revolution for 1.8-degree motors.
Whenever the microstep size is changed the System loses its Home position reference. Thus
if the RE command is to be used it should be the first command executed after power up,
and should be followed by an FH ("Find Home") command or a manual re-reference.
Alternatively, you can change the power-up default resolution via the PE ("Personality")
command.
Another way to increase travel is via the SP ("Set Position Counters") command. You can
move from one end of the travel to the other, and then reset the position counters to their
original values. This effectively moves the entire coordinate system to a different place,
giving increased travel with no sacrifice in resolution.
Motor Direction
The motors should be physically and electrically connected so that travel toward
lower-numbered coordinates produces motion towards the Home switch in each axis. If
your mechanical setup or wiring is such that the motor travel is backwards you can reverse
the direction within the Automove controller. See personality parameters 29, 30, and 31 in
Chapter 7 Changing the Personality.