Mitsubishi Electric Melsec FX Series Beginners Manual page 45

MELSEC FX PLC positioning
Applicable
Model
FX
1S
FX
1N
FX
3G
FX
3GC
FX
3GE
FX
3S
FX
3U
FX
3UC
FX
1S
FX
1N
FX
3G
FX
3GC
FX
3GE
FX
3U
FX
3UC
FX
1S
FX
1N
FX
3G
FX
3GC
FX
3GE
FX
3S
FX
3U
FX
3UC
FX
3U
FX
3UC
FX
3G
FX
3GC
FX
3GE
FX
3S
FX
3U
FX
3UC
FX
3G
FX
3GC
FX
3GE
FX
3U
FX
3UC
Tab. 4-3: Instructions for FX PLCs (2)
FX Positioning Control Systems
Description
1-speed positioning
A start command acceler-
ates the motor to a con-
stant speed and moves the
workpiece to a specified
distance.
Zero return
The machine moves at a
specified speed until the
DOG input turns ON. The
workpiece then slows to
creep speed and stops
before the CLEAR signal is
output.
Variable speed operation
After starting with a speci-
fied speed, the motor can
change its speed depend-
ing on commands from the
PLC.
(For the FX and FX ,
1S 1N
acceleration to different
speeds is approximated
with the RAMP instruction.)
Interrupt 1-speed
positioning
When an interrupt signal
turns ON, the workpiece
travels a specific distance at
the same speed before
decelerating to stop.
DOG search zero return
The machine operates simi-
lar to the zero return
instruction except for fea-
tures to hunt for the DOG
switch and to use the
zero-phase signal.
Table operation
For programming simplic-
ity, position and speed data
can be organized in table
format for the DRVI, DRVA,
DVIT and PLSV instructions.
Learning to Use the FX Family for Positioning Control
Positioning
instruction
Speed
DRVI
DRVA
Start
Speed
Creep speed
ZRN
Zero point
CLEAR signal
Speed
PLSV
(RAMP)
Start
Speed
DVIT
Start
Limit
(LSR)
DSZR
Input
DTBL
Input
DTBL
DTBL
Input
DTBL
Instruction Illustration
Operation speed
Target position
Travel distance
Zero point return
DOG input ON
Start
411040da.eps
Speed change Speed change
411050da.eps
Travel distance
Interrupt input
411060da.eps
DOG
Origin
Start
411070da.eps
K1
Y0
Command are output at
Y000 in accordance to
K2
Y0
the contents of the rows
1 to 3 of the table.
Y0 K3
Axis Row No.
411080da.eps
411030da.eps
4 - 3