Danaher Motion
06/2005
Master-Slave
M-SS-005-03 Rev
E
109
Cam profiles do not need to return
to the original position at the end
of the profile.
Cam tables are calculated
either off-line and stored, or on the fly.
Cams cycle
either indefinitely or are specified to cycle a specific
number of times.
Multiple cams
are defined and linked together automatically.
The master position is processed
through the master-slave gear ratio
(
GEARRATIO
).
Issued incremental moves are summed
with the cam profile to form
the slave position command.
5.3.2.
GEARRATIO
In camming, you set the proportional constant between the master and slave
with
<axis>.GEARRATIO
. If GEARRATIO = 1, the table is matched one-to-
one to the master axis. If it is less than one, the table is driven at a speed
slower than the master is moving. For example, to run the table at half the
speed of the master:
A1.GearRatio = 0.5 'Drive cam table at half speed
The master turns two units to drive the table one unit.
GEARRATIO
is a double-precision floating-point number. To reverse the
direction of the slave, enter the ratio as a negative number. Its value is
changeable during camming, but it has to be done carefully to avoid a
position jump in the slave value due to large differences between the old and
new value.
5.3.3. Incremental
Moves
With incremental moves to the slave, the profile from the incremental move is
summed with the profile for gearing to form the slave position.
5.3.4. Cam
Tables
A cam table is a list of master/slave point-pairs that define a one-to-one
mapping of the master to the slave axis. You specify the number of point
pairs. It may be as large or as small as the application requires. The
following is a typical cam table:
CAM1.1 = (10, 20)
CAM1.2 = (20, 40)
CAM1.3 = (30, 60)
CAM1.4 = (40, 80)
CAM1.5 = (50, 100)
In cam tables, the position of both the master and slave are in the position
units of the respective axes. The individual points in the table are given at
irregular intervals. This is useful if the cam profile has long smooth sections
and sharp turns. Irregular intervals allow you to use a few points for the
smooth section and many for the sharp turns. Although the interval of master
position is irregular, it must always be greater than zero. The master position
must be monotonically increasing or decreasing in the cam table. The slave
position is not limited by this requirement.