Function To Limit Control; Speed Limit Function - Mitsubishi Electric MELSEC iQ-R-RD75P4 User Manual

7.4

Function to Limit Control

Functions to limit the control include Speed limit function, Torque limit function, Software stroke limit function, and Hardware
stroke limit function. Each function is executed by setting parameters or creating and writing a program.

Speed limit function

Speed limit function limits the command speed to a value within the setting range of Speed limit value when the command
speed during the control exceeds Speed limit value.
When the command speed exceeds the value set in [Pr.8] Speed limit value, [Md.39] In speed limit flag turns on and Speed
limit value over (Warning code: 0991H) occurs.
Relation between the speed limit function and various controls
The following table shows the relation between Speed limit function and various controls.
: Always set
: Setting not required (The set value is ignored. Set the value within the setting range, such as the initial value.)
Control type
OPR control
Major positioning control
Manual control
Control precautions
• If any axis exceeds the value in [Pr.8] Speed limit value during either of the 2-axis speed control, 3-axis speed control, and
4-axis speed control, the axis exceeding the speed limit value is controlled with the speed limit value. The speeds of the
other axes being interpolated are suppressed by the command speed ratio.
• If any axis exceeds the value in [Pr.8] Speed limit value during any of the 2-axis linear interpolation control, 3-axis linear
interpolation control, 4-axis linear interpolation control, 2-axis fixed-feed control, 3-axis fixed-feed control, 4-axis fixed-feed
control, 2-axis circular interpolation control, and 3-axis helical interpolation control, the axis exceeding the speed limit value
is controlled with the speed limit value. The speeds of the other axes being interpolated are suppressed by the movement
amount ratio.
• In the 2-axis linear interpolation control, 3-axis linear interpolation control, 4-axis linear interpolation control, 2-axis fixed-
feed control, 3-axis fixed-feed control, or 4-axis fixed-feed control, when 1: Reference axis speed is set in [Pr.20]
Interpolation speed specification method, and when the reference axis is the minor axis and the interpolation axis is the
major axis, the speed limit value of the interpolation axis may not function.
• In the 3-axis helical interpolation control, the composite speed of the circular interpolation axis or the speed of the linear
interpolation axis is controlled not to exceed the value in [Pr.8] Speed limit value.
7 CONTROL SUB FUNCTIONS
230
7.4 Function to Limit Control
Machine OPR control
Fast OPR control
Position control 1-axis linear control
2-/3-/4-axis linear
interpolation control
1-axis fixed-feed control
2-/3-/4-axis fixed-feed
control
2-axis circular
interpolation control
3-axis helical
interpolation control
1-/2-/3-/4-axis speed control
Speed-position switching control, Position-speed
switching control
Other controls Current value change
JUMP instruction, NOP
instruction, LOOP to
LEND
JOG operation, Inching operation
Manual pulse generator operation
Speed limit function Speed limit value

[Pr.8] Speed limit value









 Setting value is invalid


[Pr.31] JOG speed limit value

Setting value is invalid