Mitsubishi Electric MELSEC iQ-R RD75P4, User Manual

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7 CONTROL SUB FUNCTIONS
7.1 Overview of Sub Functions
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7
CONTROL SUB FUNCTIONS
This chapter describes the details and usage of Sub function added and used in combination with the main functions.
A variety of sub functions, including sub functions specific to machine OPR and generally related functions such as control
compensation, are available. More appropriate and finer control can be performed by using these sub functions.
Each sub function is used together with a main function by setting parameters or creating programs. Check the settings and
execution procedures for each sub function, and configure each setting as required.
7.1
Overview of Sub Functions
Sub functions compensate or limit the control, or add functions to the control at the execution of a main function. These sub
functions are executed by setting parameters, commanding from an engineering tool, or using a program for sub functions.
Overview of sub functions
The following table shows sub functions.
Sub function Description
Sub functions
specific to machine
OPR OPR retry function Retries the machine OPR with the upper/lower limit switches during the machine OPR. This allows the
machine OPR to be performed even if the axis is not returned to a position before the near-point dog with
operations such as the JOG operation.
OP shift function After the machine OPR, this function compensates the position by the specified distance from the machine
OP position and sets that position as the OP address.
Function to
compensate control Backlash compensation
function Compensates the backlash amount of the machine system. Feed pulses 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. A flexible positioning system that matches the machine system can be structured
with this function.
Near pass function
*1
Suppresses the machine vibration when positioning data is switched during the continuous path control in
the interpolation control.
Output timing selection
of near pass control This function allows the user to select the timing to output the difference (

d) between the actual and the
set positioning end addresses in the continuous path control, in which the difference (

d) is output during
the execution of the next positioning data.
Function to limit
control Speed limit function If the command speed exceeds [Pr.8] Speed limit value during the control, this function limits the command
speed to within the setting range of [Pr.8] Speed limit value.
Torque limit function
*2
If the torque generated by the servo motor exceeds [Pr.17] Torque limit setting value during the control, this
function limits the generated torque to within the setting range of [Pr.17] Torque limit setting value.
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 the positioning for that command.
Hardware stroke limit
function Performs the deceleration stop with the limit switch connected to the RD75's connector for external
devices.
Functions that
change control
details Speed change function Changes the speed during positioning. Set the new speed in [Cd.14] New speed value, the speed change
buffer memory area, and change the speed with [Cd.15] Speed change request.
Override function Changes the speed during positioning within a percentage of 0 to 300%. Execute this function using
[Cd.13] Positioning operation speed override.
Acceleration/
deceleration time
change function Changes the acceleration/deceleration time at the speed change (function added to the speed change
function and override function).
Torque change function Changes Torque limit value during the control.
Target position change
function Changes the target position during positioning. The position and speed can be changed simultaneously.
Function related to
positioning start Pre-reading start
function If the positioning start is requested while Execution prohibition flag is on, no pulse is output, and when
Execution prohibition flag is turned off and detected, outputting pulses is started within 0.88ms.
Start time adjustment
function After the start trigger was input with the quick start function, this function starts outputting pulses after the
preset time has passed.
Absolute position restoration function
*3
Restores the absolute position of a specified axis. The OPR after the system is powered on is not required
once the OPR is executed at the startup of the system.