Omron NSJ CONTROLLERS - 03-2008 Operation Manual page 20

Safety Precautions
!WARNING
!WARNING
!WARNING
!Caution Execute online edit only after confirming that no adverse effects will be
!Caution Confirm safety at the destination node before transferring a program to
!Caution When setting Units using the IORD or IOWR instructions, check the operation
• The NSJ Controller will turn OFF all outputs when its self-diagnosis func-
tion detects any error or when a severe failure alarm (FALS) instruction is
executed. As a countermeasure for such errors, external safety measures
must be provided to ensure safety in the system.
• The NSJ Controller outputs may remain ON or OFF due to deposition or
burning of the output relays or destruction of the output transistors. As a
countermeasure for such problems, external safety measures must be
provided to ensure safety in the system.
Confirm safety before transferring data files stored in the file memory (Mem-
ory Card or EM file memory) to the I/O area (CIO) of the Controller Section
using a Programming Device. Otherwise, the devices connected to Output
Units may malfunction regardless of the operation mode of the Controller Sec-
tion.
Fail-safe measures must be taken by the customer to ensure safety in the
event of incorrect, missing, or abnormal signals caused by broken signal lines,
momentary power interruptions, or other causes. Serious accidents may
result from abnormal operation if proper measures are not provided.
The NSJ Controller refreshes I/O even when the program is stopped (i.e.,
even in PROGRAM mode). Confirm safety thoroughly in advance before
changing the status of any part of memory allocated to Output Units, Special
I/O Units, or CPU Bus Units. Any changes to the data allocated to any Unit
may result in unexpected operation of the loads connected to the Unit. Any of
the following operations may result in changes to memory status.
• Transferring I/O memory data to the Controller Section from a Program-
ming Device.
• Changing present values in memory from a Programming Device.
• Force-setting/-resetting bits from a Programming Device.
• Transferring I/O memory files from a Memory Card or EM file memory to
the Controller Section.
• Transferring I/O memory from a host computer or from another node on a
network.
caused by extending the cycle time. Otherwise, the input signals may not be
readable.
another node or changing contents of the I/O memory area. Doing either of
these without confirming safety may result in injury.
of the ladder program and data completely before using them in actual opera-
tion. Incorrect settings may cause the Unit to stop operating or may result in
unexpected operation of connected devices.
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