MOTION CONTROL
ADVANCED MICRO CONTROLS INC.
2
16
Defining Home Position (continued)
Find Home CW & Find Home CCW Commands (continued)
In addition to homing the machine with a discrete DC sensor, the SD17060E can be homed to an encoder Z-
Pulse. This encoder is typically mounted on the motor but it can be mounted anywhere on the machine. In
most cases, the encoder completes multiple rotations over the complete travel of the machine. In order to
home the machine to the correct pulse, the SD17060E has a Home Proximity bit defined in its Network Out-
put Data. When this bit is enabled, the SD17060E will ignore all transitions on the Home Limit input while
the Home Proximity bit = 0.
Homing Operation To Encoder Z-Pulse with Home Proximity Bit
Figure 2.8 Homing with Encoder Z-Pulse
1) Begin move at the Starting Speed and accelerate to Programmed Speed.
2) Run at the Programmed Speed.
3) Ignore Home Limit (Z-Pulse) because the Home Proximity Bit is not set.
4) Decelerate to the Starting Speed when the Home Proximity Bit transitions from Off to On.
5) Run at the programmed Starting Speed until the Home Limit (Z-Pulse) transitions from Inactive to
Active.
Manual, Relative, and Absolute Moves
The SD17060E performs three basic types of moves.
h
Manual Moves –
The motor rotates in the programmed direction as long as the command bit is active.
These moves can be stopped with an external switch, or sensor, brought directly into the SD17060E.
h
Relative Moves –
The motor rotates in the programmed direction for the specified number of counts.
h
Absolute Moves –
The motor rotates from the present, known position to a programmed position. The
number of counts to move and the direction of rotation are determined by the differ-
ence between the current and target positions.
You can mix all types of moves when running your machine. For example, once the machine
is homed, you can perform an Absolute Move to a specific location followed by a Relative
Move.
Manual Moves
Manual Moves are controlled with two bits in the Network Output Data. A “1” on the CW Manual Move bit
commands a clockwise move while a “1” on the CCW Manual Move bit commands a counter-clockwise
move. The move continues as long as the command bit is set. Note that both bits cannot be set at the same
time.
Manual Moves are typically used to drive the machine under direct operator control. Manual Moves can also
be used when you are interested in controlling the speed of the shaft instead of its position. One such applica-
tion is driving a conveyor belt. In this application you are only interested in driving the conveyor at a specific
speed, and you may need to vary the speed based on environmental conditions.
(CW)
(CCW)
SP
EE
D
POSITION
Starting Speed
Starting Speed
Backplane
Proximity
Bit
➀
➀
➀
➀
➁
➁
➁
➁
➃
➃
➃
➃
➄
➄
➄
➄
Home
Input
Home
Input
➂
➂
➂
➂
