Omron PROFINET NX-PNC202 User Manual page 21

Units that supply power continue to supply power to the Units for up to several seconds after the
power supply is turned OFF. The PWR indicator remains lit as long as power is supplied. Confirm that
the PWR indicator is not lit before you perform any of the above.
Operation
• Confirm that the controlled system will not be adversely affected before you perform any of the fol-
lowing operations.
Changing the operating mode of the CPU Unit or Industrial PC (including changing the setting of the
Operating Mode at Startup)
Changing the user program or settings
Changing set values or present values
Forced refreshing
• Always sufficiently check the safety at the connected devices before you change the settings of an IO
Device or Unit.
PROFINET Communications
• Make sure that the communications distance, number of nodes connected, and method of connec-
tion for PROFINET are within specifications.
Do not connect PROFINET Coupler Units to an EtherCAT network.
• Malfunctions or unexpected operation may occur for some combinations of PROFINET revisions of
the IO Controller and IO Devices. If you disable the revision check in the network settings, check the
PROFINET IO Device revision settings in the IO Controller and the actual IO Device revisions, and then
make sure that functionality is compatible in the manuals or other references. You can check the IO
Device versions in the settings from the Sysmac Studio and you can check the actual IO Device revi-
sions from the Sysmac Studio or on IO Device nameplates.
• After you transfer the user program, the CPU Unit is restarted and communications with the Profinet
IO Devices are cut off. During that period, the IO Device outputs behave according to the IO Device
settings.
The time that communications are cut off depends on the PROFINET network configuration.
Before you transfer the user program, confirm that the system will not be adversely affected.
• PROFINET communications are not always established immediately after the power supply is turned
ON. Use the IO Device terminal status bits in the user program to confirm that communications are
established before attempting control operations.
• If frames sent to Profinet IO Devices are lost due to noise or other causes, IO Device IO data is not
communicated, and the intended operation is sometimes not achieved. Perform the following pro-
cessing if noise countermeasures are necessary.
Program the IO Device Terminal Status and/or Unit status bits as an interlock condition in the user
program.
Refer to the third party IO Controller Manual for details.
• When a Profinet IO Device is disconnected, communications will stop and control of the outputs will
be lost not only for the disconnected IO Device, but for all IO Devices connected after it. Confirm that
the system will not be adversely affected before you disconnect an IO Device.
• If you disconnect the cable from a Profinet IO Device to disconnect it from the network, any current
communications frames will be lost. If communication frames are lost, then the IO Device data is not
communicated, and the intended operation is not achieved. Perform the following processing for an
IO Device that needs to be replaced.
Program the IO Device Terminal Status and/or Unit status CIO bits as an interlock condition in the
user program.
• All PROFINET communications shall be contained in a separate network from general networks to
prevent unintended PROFINET communication failures.
NX-series PROFINET Coupler Unit User's Manual (W623)
Precautions for Safe Use
19