Mitsubishi Electric MELSEC-L LD75D, User Manual

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CHAPTER 9 MAJOR POSITIONING CONTROL
9
9.
2 Set
ting t
he Pos
itioning
D
at
a
9.2.7
2-axis fixed-feed control (interpolation)
In "2-axis fixed-feed control" ("[Da.2] Control system" = 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 the movement amount designated in the positioning data is rounded down if
less than that required for control accuracy to output the same amount of pulses.
(Refer to

Page 359, Section 9.1.6 for details on interpolation control.)
(1) 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.
(2) Restrictions
• The axis 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.)
• 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
)".)
• "Fixed-feed" cannot be set in "[Da.2] Control system" 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 axis 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.
Designated movement
amount
Designated movement
amount
(0,0)
(0,0)
(0,0)
X axis
Y axis
" Md. 20 Current feed value" of each axis
is set to "0" at the positioning start