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
Electronic Cam
The electronic cam is a motion control mode which enables the periodic synchronization of several axes of motion.
Up to 7 axes can be slaved to one master axis. The master axis encoder must be input through a main encoder
port.
The electronic cam is a more general type of electronic gearing which allows a table-based relationship between
the axes. It allows synchronizing all the controller axes. For example, the DMC-4080 controllers may have one
master and up to seven slaves.
To illustrate the procedure of setting the cam mode, consider the cam relationship for the slave axis Y, when the
master is X. Such a graphic relationship is shown in Figure 6.13.
Step 1. Selecting the master axis
The first step in the electronic cam mode is to select the master axis. This is done with the instruction
EAp where p = X,Y,Z,W,E,F,G,H
p is the selected master axis
For the given example, since the master is x, we specify EAX
Step 2. Specify the master cycle and the change in the slave axis (or axes).
In the electronic cam mode, the position of the master is always expressed modulo one cycle. In this example, the
position of x is always expressed in the range between 0 and 6000. Similarly, the slave position is also redefined
such that it starts at zero and ends at 1500. At the end of a cycle when the master is 6000 and the slave is 1500,
Chapter 6 Programming Motion ▫ 92
DMC-40x0 User Manual