Delta Tau GEO BRICK LV User Manual

Turbo PMAC User Manual

Motor Compensation Tables and Constants

167

Setup Example

In this example, Motors 1, 2, and 3 are the X, Y, and Z-axes, respectively, in Coordinate System 1 of a
Cartesian stage. Each uses quadrature feedback with 0.1-micron resolution, and is programmed in
millimeters. Motor 4 is used to control the gap height of the vertical tool over the surface. It uses a capacitive
gap sensor through an Acc-28 16-bit A/D converter, with the LSB of the ADC measuring 0.25 microns. It is
assigned to the W-axis in the same coordinate system, also programmed in millimeters (of gap).

I8003=$1F8E00

; ECT 4th entry: unsigned A/D from Y:$78E00

Gap virtual motor basic setup

I400=1

; Activate Motor 4

I401=2

; Output to an X register

I402=$10F0

; Output to open register X:$10F0

I403=@I8003

; Use result from ECT 4th entry for position

I404=@I8003

; Use result from ECT 4th entry for velocity

Vertical positioning motor link to virtual motor

I305=$10F0

; Use #4 output as master input

I307=1

; Set lowest possible master scale factor

Coordinate system setup

#1->10000X

; X-axis positioning in millimeters

#2->10000Y

; Y-axis positioning in millimeters

#3->10000Z

; Z-axis positioning in millimeters

#4->4000W

; Vertical gap in millimeters

Changing the Mode of Control

Whenever the following mode control bit is changed, re-align the relationship between the corresponding
motor and axis positions for the inner loop. While this is done automatically any time a program is
started with an R or S command, if this bit is changed in the middle of a motion program, command this
re-alignment explicitly by issuing a PMATCH command. This is an on-line command; from a motion
program, it must be issued with the CMD"PMATCH" syntax.
This command generally must be bracketed before and after with DWELL commands; the first to stop any
lookahead and blending (this can be a DWELL 0), and the second to give the on-line command time to
execute in background from the command queue before the next programmed move is calculated.

Mode Changing Example

The following code segment shows how the transition to engaging the outer loop can be accomplished.
This example continues the one above, in which the Z-axis has been assigned to the inner loop’s motor, so
it is a position axis, and the W-axis has been assigned to the outer loop’s virtual motor.

Z10

; Pure position move on inner loop

DWELL0

; Stop lookahead

I306=3

; Engage following, put in offset mode

CMD"&1PMATCH"

; Re-align motor and axis position

DWELL10

; Give PMATCH command time to execute

; Outer loop command

The following code segment shows how the transition to disengaging the outer loop can be accomplished.