Galil DMC-1800, DMC-1700 user manual Virtual Axis, ECAM Master Example, Sinusoidal Motion Example

DT2	Specify time increment
I=0	Initialize array counter
#B	Loop counter
CD DX[I]; I=I+1;WC	Specify contour data I=I+1 Increment array counter
JP #B,I<500	Loop until done
DT 0;CD0	End contour mode
EN	End program

For additional information about automatic array capture, see Chapter 7, Arrays.

Virtual Axis

The DMC-1700/1800 controller has an additional virtual axis designated as the N axis. This axis has no encoder and no DAC. However, it can be commanded by the commands:

AC, DC, JG, SP, PR, PA, BG, IT, GA, VM, VP, CR, ST, DP, RP.

The main use of the virtual axis is to serve as a virtual master in ECAM modes, and to perform an unnecessary part of a vector mode. These applications are illustrated by the following examples.

ECAM Master Example

Suppose that the motion of the XY axes is constrained along a path that can be described by an electronic cam table. Further assume that the ecam master is not an external encoder but has to be a controlled variable.

This can be achieved by defining the N axis as the master with the command EAN and setting the modulo of the master with a command such as EMN= 4000. Next, the table is constructed. To move the constrained axes, simply command the N axis in the jog mode or with the PR and PA commands.

For example, PAN = 2000

BGN

will cause the XY axes to move to the corresponding points on the motion cycle.

Sinusoidal Motion Example

The x axis must perform a sinusoidal motion of 10 cycles with an amplitude of 1000 counts and a frequency of 20 Hz.

This can be performed by commanding the X and N axes to perform circular motion. Note that the value of VS must be

VS=2π * R * F

where R is the radius, or amplitude and F is the frequency in Hz. Set VA and VD to maximum values for the fastest acceleration.

INSTRUCTION	INTERPRETATION
VMXN	Select axes
VA 68000000	Maximum Acceleration
VD 68000000	Maximum Deceleration
VS 125664	VS for 20 Hz
CR 1000, -90, 3600	Ten cycles
VE
BGS

118 • Chapter 6 Programming Motion DMC-1700/1800