Mitsubishi Electric MELSEC-L LD75P User Manual page 794

Trouble type
How long is the output time for the deviation counter
clear signal?
Is a deviation counter clear signal output when the
Deviation counter clear
positioning is complete?
How can a deviation counter clear signal be output?
The error "PLC READY OFF start" (error code: 537)
Module occurs after the LD75 is replaced.
(The program is the same.)
The motor only rotates in one direction.
Motor
Can the current motor speed be monitored?
The error "Backlash compensation amount error"
(error code: 920) occurs even when the backlash
compensation value is set to "1".
When a JOG operation is attempted, errors such as
"Hardware stroke limit (+)" or "Hardware stroke limit
(-)" (error code: 104 or 105) occur and the machine
does not move.
The error "Speed designation during OP shift error"
Error/warning
(error code: 997) appears when the PLC READY
signal [Y0] turns from OFF to ON.
When the start signal was turned ON immediately
after the stop signal ON, the warning "Start during
operation" (warning code: 100) was detected, and
the start was ignored.
Does the warning "Deceleration/stop speed
change" (warning code: 500) occur only during
"stop deceleration" and "automatically
deceleration"?
Is there any problem if the operation is continued in
that state without resetting the error?
Positioning complete Position control was executed but the positioning
signal complete signal does not turn ON.
792
Questions/Trouble Remedy
The time set in "[Pr.55] Deviation counter clear signal output time".
(Initial value: 11ms)
A signal is not output.
The only time the LD75 outputs a deviation counter clear signal is
for a machine OPR.
The LD75 does not output a deviation counter clear signal except
for machine OPR.
The internal parameters of the LD75 may be different.
Check if the LD75 READY signal [X0] turns ON when the PLC
READY signal [Y0] turns ON.
When the PLC READY signal is ON but the LD75 READY signal is
OFF, the parameter error has occurred.
Check the error code and modify the parameter with the error.
The parameter settings on the LD75 side may not match those on
the servo side.
Check the parameter settings.
The speed shown on the LD75 monitor is calculated from the
number of pulses output from the module. Thus, the actual motor
speed cannot be monitored.
("[Md.22] Feedrate" monitors the commanded speed. It does not
show the actual motor speed.)
Backlash compensation amount
0 ≤
Movement amount per pulse
Setting is not possible if the above equation is not satisfied.
Adjust by setting "[Pr.4] Unit magnification" to 10-fold (or 100-fold,
or 1000-fold), and setting "[Pr.3] Movement amount per rotation" to
1/10 (or 1/100, or 1/1000).
The hardware stroke limit wiring has probably not been carried
out.
Refer to  Page 541, Section 12.4.4 for details, and wire
accordingly.
A value besides "0" or "1" may be set in the "[Pr.56] Speed
designation during OP shift".
Review the set program, and reset the correct parameters.
The LD75 starts the deceleration stop process when the stop
signal ON is detected. Thus, the machine interprets that
"positioning is still being executed" immediately after the stop
signal ON. Even if the start signal is turned ON at that time, the
start request will be ignored and the warning "Start during
operation" (warning code: 100) will occur.
The warning occurs only at those times mentioned at the left.
Because this is a warning, there is no problem if the operation can
be continued without resetting the error.
(When the speed is changed using the override, the new value will
not be reflected on the data being executed, but will be reflected
from the next start.)
Depending on the stop occurrence factor, positioning may have
not been completed normally.
Check the axis monitor "[Md.26] Axis operation status" after the
BUSY signal has turned OFF.
Stop: The stop signal has turned ON during positioning.
Check the condition under which the stop signal (Y stop, external
stop) turns ON.
Error: An error has occurred during positioning.
Check the error occurrence factor from "[Md.23] Axis error No.".
The setting value of the detailed parameter 2 "Positioning
complete signal output time" is 0 or shorter than the scan time.
Using the program, set the time when the signal can be detected
securely.
No.
42
43
44
45
46
47
≤ 255
48
49
50
51
52
53
54