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Trouble Shooting Section 8-7
8-7 Trouble Shooting
8-7-1 Symptom at Power ON or during Operation
Note Do not repair the LCD Option Board by yourself.
8-7-2 Communication Error Message during Operation
When communication error occurs, the error message will be displayed at the
LCD Option Board and the red backlight will blink.
Symptom Probable cause Possible solution
No LCD display LCD connection error or no power supply
from PLC.
Check if LCD is connected correctly and the
PLC power supply is normal.
Still in startup waiting time. It's not error. Just wait a moment.
Display EEPROM Error
Screen and blinking red back-
light
EEPROM is damaged. Replace the LCD Option Board.
User settings in EEPROM are corrupted. Press the ESC button to exit the screen.
User settings backed up in EEPROM will be
replaced by default settings. Then proceed
to reset the screens. (See 8-7-3 for details.)
Display NG Screen
LCD connection error. Check if LCD is connected correctly.
Communication error between LCD and
PLC.
Check the communication setting of PLC,
switching DipSW4 to ON.
Display Error Screen and
blinking red backlight
PLC error Check PLC according to error code and
eliminate the error.
Button unresponsing
Button is damaged. Replace the LCD Option Board.
User setting error. Check the settings and change it.
Noise disturbing. Retry after the noise is reduced.
Display too faint
Backlight is damaged. Replace the LCD Option Board.
Contrast level is too low or too high. Reset the contrast level.
Error message Probable cause Possible solution
Parity Error or Framing Error
or Overrun Error
Communication parameters or conditions of
PLC are changed.
Check the communication setting of PLC.
LCD connection error. Check if LCD is still connected correctly.
Noise disturbing. • Return to normal automatically when the
noise is reduced.
• If the display cannot return to normal,
press the ESC button to restart LCD.
FCS Error(Sum check) Noise disturbing. • Return to normal automatically when the
noise is reduced.
• If the display cannot return to normal,
press the ESC button to restart LCD.
Buffer overflow The length of receiving data is beyond the
range of receiving memory.
Press the ESC button to restart LCD.
Noise disturbing.
Connecting Host... LCD connection error. Check if LCD is still connected correctly.
The communication between PLC and LCD
is out of service.
Check if PLC is running normally.
Response code Error Operation mistake. Refer to CJ/CS Communication Manual for
solutions according to an end code.
Noise disturbing. • Return to normal automatically if the noise
is reduced.
• Press the ESC button to exit the screen.
CX-Programmer and LCD execute some
function at the same time.
Press the ESC button to exit the screen.
Execute this function by either CX-Pro-
grammer or LCD.