Omron NJ501-1400 User Manual page 25

EtherCAT Communications
• Make sure that the communications distance, number of nodes connected, and method of connec-
tion for EtherCAT are within specifications.
Do not connect EtherCAT communications to EtherNet/IP, a standard in-house LAN, or other net-
works. An overload may cause the network to fail or malfunction.
• Malfunctions or unexpected operation may occur for some combinations of EtherCAT revisions of the
master and slaves. If you disable the revision check in the network settings, use the Sysmac Studio
to check the slave revision settings in the master and the actual slave revisions, and then make sure
that functionality is compatible in the slave manuals or other references. You can check the actual
slave revisions from the Sysmac Studio or on slave nameplates.
• 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 specifica-
tions. 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. At that time, the Servo
Drive will operate according to the Servo Drive specifications. Make sure that the Fail-soft Operation
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 will behave according to the slave specifications. Refer to the manual
for the slave. If a noise countermeasure or slave replacement is required, perform the following pro-
cessing.
• Program the Input Data Invalid system-defined variable as an interlock condition in the user pro-
gram.
• Set the PDO communications timeout detection count setting in the EtherCAT master to at least 2.
Refer to the NJ/NX-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.
• I/O data communications of NX bus 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 program to confirm that I/O data 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.
NJ-series CPU Unit Hardware User's Manual (W500)
Precautions for Safe Use
23