13. TROUBLESHOOTING
Basic troubleshooting methods are explained in this section.
For problems concerning the PLC CPU and Master Unit, consult users manuals for these units.
13.1. L ERR. INDICATOR BLINKING
CHECK
TROUBLESHOOTING
Have you changed the station No. and/or baud rate settings
during normal operation?
Return these settings to the state when the unit operated
normally.
13.2. L ERR. INDICATOR ON
CHECK
TROUBLESHOOTING
Are the station No. and/or baud rate settings correct?
Set them correctly.
13.3. L RUN INDICATOR OFF
Consult the users manual for the Master Unit.
13.4. UNABLE TO READ/WRITE DIGITAL VALUES?
CHECK
TROUBLESHOOTING
Is the L RUN indicator OFF?
Refer to Section “13.3. L RUN INDICATOR OFF”.
Is the L ERR. indicator blinking or ON?
Consult the users manual for the Master Unit.
Is the RUN indicator on the PLC CPU blinking or OFF?
Consult the users manual for the CPU.
Is the RUN indicator on the Master Unit OFF?
Consult the users manual for the Master Unit.
Are the RD/SD indicators on the Master Unit ON?
Consult the users manual for the Master Unit.
Are the wires for analog I/O properly connected to respective
terminals? No wire breakdown?
Check these wires visually or check conductivity for each pair
of wires.
Remove analog input wires and apply test voltage to the termi-
nals (e.g. Use a dry cell). Try to read out digital value.
If the digital value is read out normally, there are possibili-
ties of noise interference via external wires. Check wiring and
grounding.
R1C-GH
5-2-55, Minamitsumori, Nishinari-ku, Osaka 557-0063 JAPAN
Phone: +81(6)6659-8201 Fax: +81(6)6659-8510 E-mail: [email protected]
EM-5956 Rev.11 P. 12 / 13
