Galil DMC-13X8 Command Summary Electronic Gearing, Example Simple Master Slave, Ga Y,,Y,Y

There are two modes: standard gearing and gantry mode. The gantry mode is enabled with the command GM. GR 0,0,00 turns off gearing in both modes. A limit switch or ST command disable gearing in the standard mode but not in the gentry mode.

The command GM x,y,z,w select the axes to be controlled under the gantry mode. The parameter 1 enables gantry mode, and 0 disables it.

GR causes the specified axes to be geared to the actual position of the master. The master axis is commanded with motion commands such as PR, PA or JG.

When the master axis is driven by the controller in the jog mode or an independent motion mode, it is possible to define the master as the command position of that axis, rather than the actual position. The designation of the commanded position master is by the letter, C. For example, GACX indicates that the gearing is the commanded position of X.

An alternative gearing method is to synchronize the slave motor to the commanded vector motion of several axes performed by GAS. For example, if the X and Y motor form a circular motion, the Z axis may move in proportion to the vector move. Similarly, if X,Y and Z perform a linear interpolation move, W can be geared to the vector move.

Electronic gearing allows the geared motor to perform a second independent or coordinated move in addition to the gearing. For example, when a geared motor follows a master at a ratio of 1:1, it may be advanced an additional distance with PR, or JG, commands, or VP, or LI.

Command Summary - Electronic Gearing

COMMAND	DESCRIPTION
GA n	Specifies master axes for gearing where:
	n = X,Y,Z or W for main encoder as master
	n = CX,CY,CZ or CW for commanded position.
	n = DX,DY,DZ or DW for auxiliary encoders
	n = S or T for gearing to coordinated motion.
GR x,y,z,w	Sets gear ratio for slave axes. 0 disables electronic gearing for specified axis.
GM x,y,z,w	X = 1 sets gantry mode, 0 disables gantry mode
MR x,y,z,w	Trippoint for reverse motion past specified value. Only one field may be used.
MF x,y,z,w	Trippoint for forward motion past specified value. Only one field may be used.

Example - Simple Master Slave

Master axis moves 10000 counts at slew speed of 100000 counts/sec. Y is defined as the master. X,Z,W are geared to master at ratios of 5,-.5 and 10 respectively.

GA Y,,Y,Y	Specify master axes as Y
GR 5,,-.5,10	Set gear ratios
PR ,10000	Specify Y position
SP ,100000	Specify Y speed
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-13X8 controller, where the Z-axis is the master and X and Y are the geared axes.

Chapter 6 Programming Motion • 78 USER MANUAL