Electronic Cam - Galil Motion Control DMC-21 5 Series User Manual

Example - Gantry Mode
In applications where both the master and the follower are controlled by the DMC-21x5 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 A and B axes on both sides. This requires the gantry mode for
strong coupling between the motors. The A axis is the master and the B axis is the follower. To synchronize B with
the commanded position of A, use the instructions:
GA ,CA;
GR ,1;
GM ,1;
Profiled position corrections can also be performed while in the electronic gearing mode. Suppose, for example,
that the slave needs to be advanced by 10 counts:
IP ,10;
Under these conditions, this IP command is equivalent to:
PR ,10;
BG B;
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 ,A;
GR ,2;
PR ,300;
SP ,5000;
AC ,100000;
DC ,100000;
SH AB;
BG B;
AM B;
MO AB;
EN;

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-2185 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 B, when the
master is A. 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 with the EA command.
EA A
Chapter 6 Programming Motion ▫ 58
'specify the commanded position of A as master for B
'set gear ratio for B as 1:1
'set gantry mode
'specify incremental position move of 10 on B axis
'specify position relative movement of 10 on B axis
'begin motion on B
'define A as the master axis for B
'set gear ratio 2:1 for B
'specify correction distance
'specify correction speed
'specify correction acceleration
'specify correction deceleration
'servo A and B axes
'start correction
'wait until motion is completed
'disable A and B axes
'end program
axis
DMC-21x5 User Manual 1.0a1