Mitsubishi Electric RD77MS16, User Manual

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8 CONTROL SUB FUNCTIONS
8.1 Outline of Sub Functions
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CONTROL SUB FUNCTIONS
The details and usage of the "sub functions" added and used in combination with the main functions are explained in this
chapter.
A variety of sub functions are available, including functions specifically for machine home position return and generally related
functions such as control compensation, etc. More appropriate, finer control can be carried out by using these sub functions.
Each sub function is used together with a main function by creating matching parameter settings and programs. Read the
execution procedures and settings for each sub function, and set as required.
8.1
Outline of Sub Functions
"Sub functions" are functions that compensate, limit, add functions, etc., to the control when the main functions are executed.
These sub functions are executed by parameter settings, operation from the engineering tool, sub function programs, etc.
Outline of sub functions
The following table shows the types of sub functions available.
Sub function Details
Functions characteristic
to machine home
position return
Home position return retry
function This function retries the home position return with the upper/lower limit switches during machine
home position return. This allows machine home position return to be carried out even if the axis is
not returned to before the near-point dog with JOG operation, etc.
Home position shift
function After returning to the machine home position, this function offsets the position by the designated
distance from the machine home position and sets that position as the home position address.
Functions that
compensate control Backlash compensation
function This function compensates the mechanical backlash. Feed command equivalent to the set backlash
amount are output each time the movement direction changes.
Electronic gear function By setting the movement amount per pulse, this function can freely change the machine movement
amount per commanded pulse.
When the movement amount per pulse is set, a flexible positioning system that matches the machine
system can be structured.
Near pass function
*1
This function suppresses the machine vibration when the speed is changed during continuous path
control in the interpolation control.
Functions that limit
control Speed limit function If the command speed exceeds "[Pr.8] Speed limit value" during control, this function limits the
commanded speed to within the "[Pr.8] Speed limit value" setting range.
Torque limit function If the torque generated by the servomotor exceeds "[Pr.17] Torque limit setting value" during control,
this function limits the generated torque to within the "[Pr.17] Torque limit setting value" setting range.
Software stroke limit
function If a command outside of the upper/lower limit stroke limit setting range, set in the parameters, is
issued, this function will not execute positioning for that command.
Hardware stroke limit
function This function carries out deceleration stop with the hardware stroke limit switch.
Forced stop function This function stops the all axes of the servo amplifier when the forced stop input signal of the Simple
Motion module external input connection connector is turned ON.
Functions that change
control details
Speed change function This function changes the speed during positioning.
Set the changed speed in the speed change buffer memory ([Cd.14] New speed value), and change
the speed with the speed change request ([Cd.15] Speed change request).
Override function This function changes the speed within a percentage of 0 to 300% during positioning. This is
executed using "[Cd.13] Positioning operation speed override".
Acceleration/deceleration
time change function
This function changes the acceleration/deceleration time during speed change.
Torque change function This function changes the "torque limit value" during control.
Target position change
function This function changes the target position during the execution of positioning. At the same time, this
also can change the speed.
Functions related to
positioning start
Pre-reading start function This function shortens the virtual start time.
Absolute position system function This function restores the absolute position of designated axis.