Function To Compensate Control; Backlash Compensation Function - Mitsubishi Electric MELSEC iQ-F Series FX5 User Manual

12.3

Function to Compensate Control

The functions to compensate the control include Backlash compensation function, Electronic gear function, Near pass
function, and Output timing selection of near pass control. Each function is executed by setting parameters or creating and
writing a program.

Backlash compensation function

This function compensates the backlash amount in the machine system.
When the backlash compensation amount is set, pulses for an extra amount equivalent to the set backlash amount are output
every time the movement direction changes.
[Pr.11] Backlash compensation amount
Control details
The following figure shows the operation of the backlash compensation function.
Forward pulse
Backlash pulses are output during the
Reverse pulse
Control precautions
• The feed pulses of the backlash compensation amount are not added to [Md.20] Current feed value or [Md.21] Machine
feed value.
• Always perform the machine OPR before starting the control when using the backlash compensation function (when [Pr.11]
Backlash compensation amount is set). If the machine OPR is not performed, the backlash amount in the machine system
cannot be correctly compensated.
• The number of pulses output in one backlash compensation (value determined by dividing the value in [Pr.11] Backlash
compensation amount by Movement amount per pulse) must be 255 or smaller. If 256 or larger value is set, Backlash
compensation amount error (Error code: 1AA0H) occurs. (Depending on the connected servo motor, tracking may not be
possible if a large number of pulses are output at once.)
Backlash compensation amount
0 ≤
Movement amount per pulse
• The backlash compensation including the movement amount and [Pr.11] Backlash compensation amount is output when
the moving direction changes.
• The backlash compensation function cannot be used for an axis where a stepping motor is connected. Set 0 (initial value)
in [Pr.11] Backlash compensation amount.
12 CONTROL SUB FUNCTION
218
12.3 Function to Compensate Control
Feed screw
Workpiece
1.77ms of reversal time.
Reversal timing
≤ 255 (Omit values after the decimal point)
1.77 ms
t