MITSUBISHI ELECTRIC Mitsubishi Programmable Logic Controller QD75D - Manual (Page 371)

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MELSEC-Q
9 MAJOR POSITIONING CONTROL
Current feed value during 2-axis speed control
The following table shows the " Md.20 Current feed value" during 2-axis speed
control corresponding to the " Pr.21 Current feed value during speed control"
settings. (Note that the reference axis setting values are used for parameters.)
" Pr.21 Current feed value during speed
control" setting
Md.20 Current feed value
0: Do not update current feed value
The current feed value at speed control start
is maintained.
1: Update current feed value The current feed value is updated.
2: Zero clear current feed value The current feed value is fixed at 0.
Speed
t
In speed control
Current feed value during speed control start is maintained
(a) Current feed value not updated
t
Current feed value is updated
(b) Current feed value updated (c) Current feed value zero cleared
t
0
Speed In speed control In speed control Speed
Restrictions
(1) Set "Positioning complete" in " Da.1 Operation pattern". An axis error
"Continuous path control not possible (error code: 516)" will occur and the
operation cannot start if "continuous positioning control" or "continuous path
control" is set.
("Continuous positioning control" and "continuous path control" cannot be set
in speed control.)
(2) Set the WITH mode in " Pr.18 M code ON signal output timing" when using
an M code. The M code will not be output, and the M code ON signal will not
turn ON if the AFTER mode is set.
(3) Set the "reference axis speed" in " Pr.20 Interpolation speed designation
method". An "Interpolation mode error (error code: 523)" will occur and the
operation cannot start if a composite speed is set.
(4) When either of two axes exceeds the speed limit, that axis is controlled with
the speed limit value. The speeds of the other axes are limited at the ratios of
" Da.8 Command speed".
(Examples)
Axis
Setting item
Axis 1 setting Axis 2 setting
Pr.8 Speed limit value 4000.00mm/min 5000.00mm/min
Da.8 Command speed 8000.00mm/min 6000.00mm/min
With the settings shown above, the operation speed in speed control is as
follows.
Axis 1: 4000.00 mm/min (Speed is limited by Pr.8 ).
Axis 2: 3000.00 mm/min (Speed is limited at an ratio of an axis 1 command
speed to an axis 2 command speed).