650
Troubleshooting Unit Errors
Section 12-4
Outputs
Symptom
Cause
Remedy
Not all outputs turn ON
(1) Load is not supplied with power.
Supply power
(2) Load voltage is low.
Adjust voltage to within rated range.
(3) Terminal block screws are loose.
Tighten screws
(4) Faulty terminal block connector contact.
Replace terminal block connector.
(5) An overcurrent (possibly caused by a
short at the load) resulted in a blown
fuse for the output or the Unit is faulty.
Replace fuse or Unit.
(6) Faulty I/O bus connector contact.
Replace Unit.
(7) Output circuit is faulty.
Replace Unit.
(8) If the INH indicator is lit, the Output OFF
Bit (A500.15) is ON.
Turn A500.15 OFF.
Not all outputs turn OFF
Output circuit is faulty.
Replace Unit.
Output of a specific bit num-
ber does not turn ON or indi-
cator is not lit
(1) Output ON time too short because of a
mistake in programming.
Correct program to increase the time that
the output is ON.
(2) Bit status controlled by multiple instruc-
tions.
Correct program so that each output bit is
controlled by only one instruction.
(3) Faulty output circuit.
Replace Unit.
Output of a specific bit num-
ber does not turn ON (indica-
tor lit).
(1) Faulty output device.
Replace output device.
(2) Break in output wiring.
Check output wiring.
(3) Loose terminal block screws.
Tighten screws.
(4) Faulty terminal block connector faulty.
Replace terminal block connector.
(5) Faulty output bit (relay output only).
Replace Unit.
(6) Faulty output circuit (relay output only).
Replace Unit.
Output of a specific bit num-
ber does not turn OFF (indi-
cator is not lit).
(1) Faulty output bit.
Replace Unit.
(2) Bit does not turn OFF due to leakage
current or residual voltage.
Replace external load or add dummy resis-
tor.
Output of a specific bit num-
ber does not turn OFF (indi-
cator lit).
(1) Bit status controlled by multiple instruc-
tions.
Correct program.
(2) Faulty output circuit.
Replace Unit.
Output irregularly turns ON/
OFF.
(1) Low or unstable load voltage.
Adjust load voltage to within rated range
(2) Bit status controlled by multiple instruc-
tions.
Correct program so that each output bit is
controlled by only one instruction.
(3) Malfunction due to noise.
Protective measures against noise:
• Install surge suppressor.
• Install insulation transformer.
• Use shielded cables between the output
terminal and the load.
(4) Terminal block screws are loose.
Tighten screws.
(5) Faulty terminal block connector contact.
Replace terminal block connector.
Error occurs in units of
8 points or 16 points, i.e., for
the same common.
(1) Loose common terminal screw.
Tighten screws.
(2) Faulty terminal block connector contact.
Replace terminal block connector.
(3) An overcurrent (possibly caused by a
short at the load) resulted in a blown
fuse for the output or the Unit is faulty.
Replace fuse or Unit.
(4) Faulty data bus.
Replace Unit.
(5) Faulty CPU.
Replace CPU Unit.
Output indicator is not lit
(operation is normal).
Faulty indicator.
Replace Unit.
Summary of Contents for CP1L-EL20DR-D
Page 3: ...CP1L EL20D CP1L EM30D CP1L EM40D CP1L EL EM CPU Unit Operation Manual Produced July 2017...
Page 4: ...iv...
Page 10: ...x...
Page 22: ...xxii...
Page 34: ...xxxiv Software Licenses and Copyrights 7...
Page 192: ...158 Trial Operation and Debugging Section 5 3...
Page 250: ...216 Automatic Clock Adjustment and Specifying Servers by Host Name Section 6 7...
Page 666: ...632 Trouble Shooting Section 11 7...
Page 696: ...662 Standard Models Appendix A...
Page 805: ...771 Connections to Serial Communications Option Boards Appendix F Connecting to Unit...
Page 806: ...772 Connections to Serial Communications Option Boards Appendix F...
Page 836: ...802 PLC Setup Appendix G...
Page 838: ...804 TCP Status Transitions Appendix H...
Page 840: ...806 Ethernet Network Parameters Appendix I...
Page 842: ...808 Buffer Configuration CP1L EL EM Appendix J...
Page 844: ...810 Ethernet Specifications Appendix K...
Page 851: ...Index 817 work words 118 write protection 447...
Page 852: ...818 Index...
Page 854: ...820 Revision History...
Page 855: ......