Omron CJ1W-ECT21 Operation Manual page 15

The CPU Unit 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 I/O 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
operation may result in changes to memory status.
• Transferring I/O memory data to the CPU Unit from a programming 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 CPU Unit.
• Transferring I/O memory from a host computer or from another Controller
on a network.
The CPU Unit will turn OFF all outputs from Basic Output Units in the follow-
ing cases. The slaves will operate according to the settings in the slaves.
• If an error occurs in the power supply
• If the power supply connection becomes faulty
• If a CPU watchdog timer error or CPU reset occurs
• If a major fault level Controller error occurs
• While the CPU Unit is on standby until RUN mode is entered after the
power is turned ON
External safety measures must be provided to ensure safe operation of the
system in such cases.
Downloading
Always confirm safety at the destination before you transfer a user program,
configuration data, setup data, device variables, or values in memory used
for CJ-series Units from the Sysmac Studio. The devices or machines may
perform unexpected operation regardless of the operating mode of the CPU
Unit.
Actual Operation
Check the user program, data, and parameter settings for proper execution
before you use them for actual operation.
Voltage and Current Inputs
Make sure that the voltages and currents that are input to the Units and
slaves are within the specified ranges.
Inputting voltages or currents that are outside of the specified ranges may
cause accidents or fire.
CJ-series EtherCAT Slave Units Operation Manual for NJ-series CPU Unit (W542)
Safety Precautions
13