Mitsubishi Electric MELSEC-L Series, User Manual

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9 - 52
Chapter 9 Major Positioning Control
9.2.7 2-axis fixed-feed control (interpolation)
In "2-axis fixed-feed control" ("
Da.2
Control method
" = fixed-feed 2), two motors are
used to carry out fixed-feed control in a linear path while carrying out interpolation for
the axis directions set in each axis.
In fixed-feed control, any remainder of below control accuracy is rounded down to
convert the movement amount designated in the positioning data into the command
value to servo amplifier.
(Refer to Section 9.1.6 "Interpolation control" for details on interpolation control.)
Operation chart
In incremental system 2-axis fixed-feed control, the addresses (
Md.20
Current feed
value
) of the current stop position (start addresses) of both axes are set to "0".
Linear interpolation positioning is then carried out from that position to a position at
the end of the movement amount set in "
Da.6
Positioning address/movement amount
".
The movement direction is determined by the sign of the movement amount.
• Positive movement amount .............. Positioning control to forward direction
(Address increase direction)
• Negative movement amount ............. Positioning control to reverse direction
(Address decrease direction)
" Md. 20 Current feed value" of each axis
is set to "0" at the positioning start
(0,0)
(0,0)
(0,0)
X axis
Y axis
Designated
movement
amount
Designated
movement
amount
Restrictions
(1) The error "Continuous path control not possible" (error code: 516) will occur
and the operation cannot start if "continuous path control" is set in "
Da.1
Operation pattern
". ("Continuous path control" cannot be set in fixed-feed
control.)
(2) If the movement amount of each axis exceeds "1073741824 (=2
30
)" when "0:
Composite speed" is set in "
Pr.20
Interpolation speed designation method
", the
error "Outside linear movement amount range" (error code: 504) occurs at a
positioning start and positioning cannot be started. (The maximum movement
amount that can be set in "
Da.6
Positioning address/movement amount
" is
"1073741824 (= 2
30
)".
(3) "Fixed-feed" cannot be set in "
Da.2
Control method
" in the positioning data
when "continuous path control" has been set in "
Da.1
Operation pattern
" of the
immediately prior positioning data. (For example, if the operation pattern of
positioning data No. 1 is "continuous path control", fixed-feed control cannot
be set in positioning data No. 2.) The error "Continuous path control not
possible" (error code: 516) will occur and the machine will carry out a
deceleration stop if this type of setting is carried out.