User guide

204 6000 Series Programmer's Guide
Electronic Gearbox Application for Ratio Following
An electronic gearbox is a classic application for Ratio Following. Suppose we need a three-
output gearbox, with all three outputs geared off the same input. Also, each gear ratio must
be individually programmed. In this example, a 1000-line encoder is mounted to the input
shaft of a master motor, giving 4000 master counts per revolution after quadrature. This
encoder is fed into the encoder input on axis #4 (ENCODER 4 connector) of the 6000 controller.
The motors on axes 1, 2, and 3 have resolutions of 2000, 4000, and 5000 steps/revolution.
In this example, a precise position relationship is not required between master and slaves, but
a ratio change during motion is required. The ratio change will take place over one master
revolution in order to avoid abrupt acceleration of the slave. The slaves will accelerate to their
initial ratios (in terms of revolutions), and after 10 seconds the gear ratio on each axis will
change to their final ratios.
In this example, ENCODER 4 is specified as the master. This means that this external master
encoder is wired to the 6000 controller's axis #4 encoder input.
Program
(code portion)
SCALE1 ; Enable scaling
SCLD2000,4000,5000 ; Set slave scale factors equal to the motor resolutions
SCLA2000,4000,5000 ; Set acceleration scale factors equal to the
; motor resolutions
SCLMAS4000,4000,4000 ; Master scale factor to number of pulses per rev
COMEXC1 ; Allow continuous command execution during motion
FOLMAS+41,+41,+41 ; Encoder #4 is master axis for slave axes #1 - #3.
; The + sign indicates that the master input is not
; inverted before it is read as master counts.
FOLEN111 ; Enable slaves to follow
FOLMD1 ; Change to new ratio over one master revolution
FOLRN1,3,2 ; Set slave-to-master ratio numerators to 1, 3, and 2
FOLRD1,1,1 ; Set all slave-to-master ratio denominators to 1
; (initial Following ratio for axis 1 is 1:1, axis 2
; is 3:1, and axis 3 is 2:1)
MC111 ; Enable continuous mode
GO111 ; Begin slave continuous Following move
TIMST0 ; Reset and start the timer
FOLRN10,6,1 ; Set slave-to-master ratio numerators to 10, 6, and 1
FOLRD1,7,2 ; Set slave-to-master ratio denominators to 1, 7 and 2
; (change Following ratios: axis 1 is 10:1, axis 2 is 6:7,
; axis 3 is 1:2)
WAIT(TIM>=10000) ; Wait 10 seconds to change to new ratio
GO111 ; Start moving to new ratio