Error Processing and Correction
Section 5-3
5-3 Error Processing and Correction
CPU Rack/Expansion CPU Rack/Expansion I/O Rack
Symptom
Cause
Remedy
POWER indicator is unlit.
RUN indicator is unlit.
PCB short-circuited or damaged by heat.
(1) START input terminals are OFF.
(2) Error in program.
Replace Power Supply Unit or Backplane.
Short-circuit START input terminals.
Correct program
(3) Power line is faulty.
Replace Power Supply Unit.
Replace Power Supply Unit.
RUN output does not
turn ON.
Internal circuitry of
Power Supply Unit is faulty.
RUN indicator lit.
Link Unit or CPU Bus Unit
does not operate or malfunc-
tions.
(1) CPU cable is faulty.
(2) CPU bus is faulty.
(3) Expansion CPU Rack is faulty.
I/O bus faulty.
Replace CPU cable.
Replace Backplane.
Replace I/O Control or I/O Interface Unit.
Replace Backplane.
Bit does not operate.
Error occurs in units of 8
points.
(1) I/O cable is faulty.
(2) I/O bus is faulty.
Replace I/O cable.
Replace Backplane.
(3) Expansion I/O Rack is faulty.
I/O bus is faulty.
Replace I/O Control or I/O Interface Unit.
Replace Backplane.
I/O bit turns ON
All bits for one Unit do not
turn ON.
I/O bus is faulty.
Replace Backplane.
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OMRON [ OMRON ELECTRONICS LLC ]
