Omron NJ Series Troubleshooting Manual

1 Overview of Errors
1-4
NJ-series Troubleshooting Manual (W503)
1-2 Fatal Errors
This section describes the errors that cause the operation of the NJ-series CPU Unit to stop.
Software connections to the Sysmac Studio or an NS-series PT cannot be made if there is a fatal error
in the Controller.
 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 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 go online with the CPU Unit
from the Sysmac Studio. Refer to Section 2 Error Troubleshooting Methods for information on identify-
ing errors and corrections.
* Power Supply Errors and Incorrect Power Supply Unit Connected errors can be differentiated with the indicators.
There is no need to see if you can go online with the CPU Unit from the Sysmac Studio.
1-2-1 Types of Fatal Errors
1-2-2 Checking for Fatal Errors
Indicators
Going online from
the 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 Supply 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