Omron CJ1W-EIP21 Operation Manuals page 30

Precautions for Safe Use
• After you transfer the user program, the CPU Unit is restarted and communications with the Ether-
CAT slaves are cut off. During that period, the slave outputs behave according to the slave settings.
The time that communications are cut off depends on the EtherCAT network configuration.
Before you transfer the user program, confirm that the system will not be adversely affected.
• If the Fail-soft Operation parameter is set to stop operation, process data communications will stop
for all slaves when an EtherCAT communications error is detected in a slave. For this reason, if Servo
Drives are connected, the Servos for all axes will be turned OFF. Make sure that the Fail-soft Opera-
tion parameter setting results in safe operation when a device error occurs.
• EtherCAT communications are not always established immediately after the power supply is turned
ON. Use the system-defined variables in the user program to confirm that communications are estab-
lished before attempting control operations.
• If noise occurs or an EtherCAT slave is disconnected from the network, any current communications
frames may be lost. If frames are lost, slave I/O data is not communicated, and unintended operation
may occur. The slave outputs behave according to the slave settings. For details, refer to relevant
manuals for each slave. If a noise countermeasure or slave replacement is required, perform the fol-
lowing processing.
• Program the _EC_InDataInvalid (Input Data Disable) system-defined variable as an interlock con-
dition in the user program.
• Set the PDO communications timeout detection count setting in the EtherCAT master to at least 2.
Refer to the NJ-series CPU Unit Built-in EtherCAT Port User's Manual (Cat. No. W505) for details.
• When an EtherCAT slave is disconnected or disabled, communications will stop and control of the
outputs will be lost not only for the disconnected slave, but for all slaves connected after it. Confirm
that the system will not be adversely affected before you disconnect or disable a slave.
• NX bus communications are not always established immediately after the power supply is turned ON.
Use the system-defined variables and the EtherCAT Coupler Unit device variables in the user pro-
gram to confirm that communications are established before attempting control operations.
• You cannot use standard Ethernet hubs or repeater hubs with EtherCAT communications. If you use
one of these, a major fault level error or other error may occur.
Motion Control
• Confirm the axis number carefully before you perform an MC Test Run.
• The motor is stopped if communications are interrupted between the Sysmac Studio and the CPU
Unit during an MC Test Run. Connect the communications cable between the computer and CPU
Unit securely and confirm that the system will not be adversely affected before you perform an MC
Test Run.
• Always execute the Save Cam Table instruction if you change any of the cam data from the user pro-
gram in the CPU Unit or from the Sysmac Studio. If the cam data is not saved, the previous condition
will be restored when the power is turned ON again, possibly causing unexpected machine operation.
• The positive drive prohibit input (POT), negative drive prohibit input (NOT), and home proximity input
(DEC) of the Servo Drive are used by the MC Function Module as the positive limit input, negative
limit input, and home proximity input. Make sure that the signal widths for all of these input signals are
longer than the control period of the MC Function Module. If the input signal widths are shorter than
the control period, the MC Function Module may not be able to detect the input signals, resulting in
incorrect operation.
Restoring Data
• You cannot back up, restore, or compare some or all of the settings for certain slaves and Units. Also,
you cannot back up, restore, or compare data for disabled slaves or Units. After you restore data, suf-
ficiently confirm that operation is correct before you start actual operation.
• The absolute encoder home offsets are backed up with a Battery in the CPU Unit as absolute
encoder information. If any of the following conditions is met, clear the absolute encoder home offsets
from the list of data items to restore, and then restore the data. Then, define the absolute encoder
home again. If you do not define home, unintended operation of the controlled system may occur.
28 CJ-series EtherNet/IP Units Operation Manual for NJ-series CPU Unit (W495)