Omron NJ Series User Manual

12-3
12 Troubleshooting
NJ-series CPU Unit Software User’s Manual (W501)
12-1 Operation after an Error
12
12-1-2 Fatal Errors in the CPU Unit
Some errors are fatal and prevent the CPU Unit from operating. This section describes the errors that
cause the operation of the CPU Unit to stop. The Sysmac Studio and NS-series PTs cannot connect
communications if a fatal error occurs.
 Power Supply Error
Power is not supplied, the voltage is outside of the allowed range, or the Power Supply Unit is faulty.
 CPU Unit Reset
The CPU Unit stopped operation because of a hardware error. Other than hardware failures, this
error also occurs at the following times.
• The power supply to an Expansion Rack is OFF.
• The I/O Connecting Cable is incorrectly installed.
• The IN and OUT connectors are reversed.
• The connectors are not mated properly.
• There is more than one I/O Control Unit on the CPU Rack or there is an I/O Control Unit on an
Expansion Rack.
 Incorrect Power Supply Unit Connected
There is a CJ-series Power Supply Unit connected to the CPU Rack. The operation of the Controller
is stopped.
 CPU Unit Watchdog Timer Error
This error occurs in the CPU Unit. This error occurs when the watchdog timer times out because of
a hardware failure or when temporary data corruption causes the CPU Unit to hang.
You can identify fatal errors based on the status of the PWR indicator on the Power Supply Unit and the
RUN and ERROR indicators on the CPU Unit, as well as by the ability to connect communications to
the Sysmac Studio.
* Power Supply Errors and Incorrect Power Supply Unit Connected errors can be differentiated with the indicators. There is
no need to check communications with the Sysmac Studio.
12-1-2 Fatal Errors in the CPU Unit
Types of Fatal Errors
Checking for Fatal Errors
Indicator
Communications
with Sysmac Studio
CPU Unit operating
status
PWR (green) RUN (green) ERROR (red)
Not lit Not lit Not lit Not possible.* Power Supply Error
Lit Not lit Not lit CPU Unit Reset
Lit Flashing (3-s intervals) Lit Incorrect Power Sup-
ply Unit Connected
Lit Not lit Lit CPU Unit Watchdog
Timer Error

Omron NJ Series Specifications

General

Brand	Omron
Model	NJ Series
Category	Controller
Language	English