Functions To Change The Control Details; Speed Change Function - Mitsubishi Electric RD77MS2 User Manual

8.5

Functions to Change the Control Details

Functions to change the control details include the "speed change function", "override function", "acceleration/deceleration
time change function", "torque change function" and "target position change function". Each function is executed by
parameter setting or program creation and writing.
Refer to the following for combination with main function.
MELSEC iQ-R Simple Motion Module User's Manual (Startup)
Both the "speed change function" or "override function" change the speed, but the differences between the functions are
shown below. Use the function that corresponds to the application.

"Speed change function"

• The speed is changed at any time, only in the control being executed.
• The new speed is directly set.
"Override function"
• The speed is changed for all control to be executed.
• The new speed is set as a percent (%) of the command speed.
"Speed change function" and "Override function" cannot be used in the manual pulse generator operation and
speed-torque control.
Speed change function
The speed control function is used to change the speed during control to a newly designated speed at any time.
The new speed is directly set in the buffer memory, and the speed is changed by a speed change command ([Cd.15] Speed
change request) or external command signal.
During the machine home position return, a speed change to the creep speed cannot be carried out after deceleration start
because the near point dog ON is detected. When the speed change function is enabled and the speed is slower than the
creep speed, the speed change is disabled and the speed accelerates to the creep speed after the near point dog ON is
detected.
Control details
The following drawing shows the operation during a speed change.
V
[Md.40] In speed change
processing flag
8 CONTROL SUB FUNCTIONS
248
8.5 Functions to Change the Control Details
Speed changes to V2.
V1
Operation during positioning by V1.
V2
V3
Speed changes to V3.
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