489
Troubleshooting Unit Errors
Section 9-4
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-L14D Series
Page 2: ...CP1L L14D CP1L L20D CP1L M30D CP1L M40D CP1L CPU Unit Operation Manual Revised June 2007...
Page 3: ...iv...
Page 9: ...x...
Page 13: ...xiv TABLE OF CONTENTS...
Page 21: ...xxii...
Page 33: ...xxxiv Conformance to EC Directives 6...
Page 65: ...32 Function Blocks Section 1 5...
Page 153: ...120 CP CPM1A series Expansion I O Unit Wiring Section 3 6...
Page 523: ...490 Troubleshooting Unit Errors Section 9 4...
Page 531: ...498 Replacing User serviceable Parts Section 10 2...
Page 563: ...530 Auxiliary Area Allocations by Function Appendix C...
Page 611: ...578 Auxiliary Area Allocations by Address Appendix D...
Page 638: ...605 Connections to Serial Communications Option Boards Appendix F Connecting to Unit...
Page 639: ...606 Connections to Serial Communications Option Boards Appendix F...
Page 669: ...636 Index...
Page 671: ...638 Revision History...