BGY Begin
motion
Example - Electronic Gearing
Objective: Run two geared motors at speeds of 1.132 and -0.045 times the speed of an external
master. The master is driven at speeds between 0 and 1800 RPM (2000 counts/rev encoder).
Solution: Use a DMC-1630 controller, where the Z-axis is the master and X and Y are the geared
axes.
MO Z
Turn Z off, for external master
GA Z, Z
Specify Z as the master axis for both X and Y.
GR 1.132,-.045
Specify gear ratios
Now suppose the gear ratio of the X-axis is to change on-the-fly to 2. This can be achieved by
commanding:
GR 2
Specify gear ratio for X axis to be 2
Example - Gantry Mode
In applications where both the master and the follower are controlled by the DMC-1600 controller,
it may be desired to synchronize the follower with the commanded position of the master, rather
than the actual position. This eliminates the coupling between the axes which may lead to
oscillations.
For example, assume that a gantry is driven by two axes, X,Y, on both sides. This requires the
gantry mode for strong coupling between the motors. The X-axis is the master and the Y-axis is
the follower. To synchronize Y with the commanded position of X, use the instructions:
GA, CX
Specify the commanded position of X as master for Y.
GR,1
Set gear ratio for Y as 1:1
GM,1
Set gantry mode
PR 3000
Command X motion
BG X
Start motion on X axis
You may also perform profiled position corrections in the electronic gearing mode. Suppose, for
example, that you need to advance the slave 10 counts. Simply command
IP ,10
Specify an incremental position movement of 10 on Y axis.
Under these conditions, this IP command is equivalent to:
PR,10
Specify position relative movement of 10 on Y axis
BGY
Begin motion on Y axis
Often the correction is quite large. Such requirements are common when synchronizing cutting
knives or conveyor belts.
Example - Synchronize two conveyor belts with trapezoidal velocity correction.
GA,X
Define X as the master axis for Y.
GR,2
Set gear ratio 2:1 for Y
PR,300 Specify
correction
distance
SP,5000 Specify
correction
speed
AC,100000 Specify
correction acceleration
DC,100000 Specify
correction deceleration
BGY Start
correction
DMC-1600
Chapter 6 Programming Motion
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