Mitsubishi Electric MELSEC-L LD75P User Manual page 425

(2) Current feed value during 3-axis speed control
The following table shows the "[Md.20] Current feed value" during 3-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
0: Do not update current feed value
1: Update current feed value
2: Zero clear current feed value
In speed control
Speed
Current feed value during speed control start is maintained
(a) Current feed value not updated
(3) Restrictions
• Set "Positioning complete" in "[Da.1] Operation pattern". The 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 in "[Da.1] Operation pattern". ("Continuous positioning control" and
"continuous path control" cannot be set in speed control.)
• 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.
• Set the "reference axis speed" in "[Pr.20] Interpolation speed designation method". The error "Interpolation
mode error" (error code: 523) will occur and the operation cannot start if a composite speed is set.
• When either of three 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)
Setting item
[Pr.8] Speed limit value
[Da.8] Command speed
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: 3000.00mm/min (Speed is limited at ratios in axes 1, 2, and 3 command speeds).
Axis 3: 2000.00mm/min (Speed is limited at ratios in axes 1, 2, and 3 command speeds).
Note: Operation runs at speed 1 when a reference axis speed is less than 1 as a result of speed limit. In addition,
when a bias speed is set, it will be the minimum speed.
• An error "No command speed" (error code: 503) will occur if a current speed (-1) is set in "[Da.8] Command
speed".
• The software stroke limit check is not carried out when the control unit is set to "degree".
The current feed value at speed control start is maintained.
The current feed value is updated.
The current feed value is fixed at 0.
In speed control
Speed
t
Current feed value is updated
(b) Current feed value updated
Axis 1 setting
4000.00mm/min
8000.00mm/min
CHAPTER 9 MAJOR POSITIONING CONTROL
[Md.20] Current feed value
In speed control
Speed
t
0
(c) Current feed value zero cleared
Axis 2 setting Axis 3 setting
5000.00mm/min 6000.00mm/min
6000.00mm/min 4000.00mm/min
9
t
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