AMCI SV160E2, Руководство пользователя, Страница: 26 / 120

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SV160E2 User Manual
ADVANCED MICRO CONTROLS INC.
26
Definitions (continued)
Home Position
The Home Position is any position on your machine that you can sense and stop at. There are two ways to
defining the Home Position. The first is using the Preset Position command to set the Profile Position and
Encoder Position registers to a known value. The second method is using one of the
Find Home commands. If
you use the unit’s Find Home commands, the motor position and encoder position registers will automatically
be set to zero once the home position is reached. Defining a Home Position is completely optional. Some
applications, such as those that use the SV160E2 for speed control, don’t require position data at all.
Count Direction
Clockwise moves will always increase the profile position and encoder position values reported back to the
host. Some of the moves, such as the Jog Move, have a positive and negative command. A positive command,
such as the +Jog Move command, will result in a clockwise rotation of the shaft.
Target Position
The Target Position is the position that you want the move to end at. There are two ways to define the Target
Position, with relative coordinates or absolute coordinates.
Relative Coordinates
Relative coordinates define the Target Position as an offset from the present position of the motor. Most
SV160E2 moves use relative coordinates.

The range of values for the Target Position when it is treated as an offset is -1,073,741,824 to
+1,073,741,823 counts. Positive offsets will result in clockwise moves, while negative offsets result in
counter-clockwise moves. Note that the Profile and Encoder Positions can be forced to roll over with
relative moves. For example, if the Profile Position equals 100,000, a relative move of +1,073,741,823
will result in a clockwise rotation for +1,073,741,823 counts. The position will roll over and stop at

-1,073,641,825.
Absolute Coordinates
Absolute coordinates treat the Target Position as an actual position on the machine. (See Home Position on
the previous page.)

The range of values for the Target Position when it is treated as an actual position on the machine is
-1,073,741,824 to +1,073,741,823 counts. The move will be clockwise if the Target Position is greater
than the Current Position and negative if the Target Position is less than the Current Position.
Immediate Stop Deceleration
In order to limit regenerative energy when decelerating a large inertial load, the SV160E2 allows you to pro-
gram a deceleration rate for immediate stops. If left at its default value of zero, the SV160E2 stop all motion
immediately. When programmed to a value between 1,500 and 15,999, the SV160E2 will decelerate at a rate
of 1,500,000 to 15,999,000 steps/sec
2
. The time to decelerate depends on the speed at which the shaft is rotat-
ing when the immediate stop is initiated. The formulas for calculating stopping time can be found in the Con-
stant Acceleration Equations section, starting on page 37. Immediate Stop Deceleration is applied under the
following conditions:

CW Limit activated

CCW Limit activated

E-Stop Input activated

Immediate Stop command accepted from the network interface

Network Communications is lost

PLC switches out of run mode (cannot be sensed on all platforms)