Galil Motion Control tut2 Page 12
MOTION PROGRAMMING
TECHNICAL REFERENCE
ELECTRONIC GEARING
INSTRUCTION
INTERPRETATION
GA Y,,Y
Y is master
GR 5,,-2.5
X ratio=5, Z ratio=-2.5
PR,10000
Specify Y distance
SP,10000
Specify Y speed
AC,250000
Specify Y acceleration
DC,250000
Specify Y deceleration
BG Y
Begin motion
Example--Electronic Gearing
The electronic gearing mode is also useful for rotating
knife applications. Suppose a rotating knife must cut
moving paper at lengths varying between 8" and 40";
the circumference of the knife equals 20". During the
cutting interval, the linear velocity of the paper and
knife must be equal.
The design approach is to run the knife in the electron-
ic gearing mode to match the paper speed then advance or
retard the knife during the non-contact interval to cut the
correct length paper. The position of the moving paper can
be sensed by an encoder with a resolution of 2000 counts
per inch. The encoder is the master and is connected to
the X axis. Suppose the resolution of the knife encoder is
20,000 counts per revolution which equals 20". This results
in 1000 counts per inch. To synchronize the two, the knife
may be set as the slave with a gear ratio of 0.5. This, how-
ever, cuts the paper at 20" sections. To cut 12" sections, the
knife must advance 8 additional inches or 8000 counts
during the non-contact interval.
The following program performs the required move. It
is assumed that a sensor connected to Input 1 indicates the
end of the cutting interval.
INSTRUCTION
INTERPRETATION
#KNIFE
Label
GA,X
Set X encoder as master
GR,0.5
Set Y gear ratio
#LOOP
AI 1
Wait for signal to end cutting interval
PR,8000
Move additional distance
BG Y
Start move
AM Y
After correction is completed
JP #LOOP
Repeat the cycle
EN
End program
Example--Rotating Knife
MASTER Y AXIS
10000
TIME
X
VELOCITY
TIME
Y
VELOCITY
TIME
Z
VELOCITY
25000
SLAVE X AXIS
SLAVE Z AXIS
50000
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Galil Motion Control, Inc.
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