Omron NJ501-1400 User Manual page 24

Precautions for Safe Use
General Communications
• When you use data link communications, check the error information that is given in _ErrSta (Control-
ler Error Status) to make sure that no error has occurred in the source device. Create a user program
that uses reception data only when there is no error in the source device. If there is an error in the
source device, the data for the data link may contain incorrect values.
• Unexpected operation may result if inappropriate data link tables are set. Even if appropriate data link
tables have been set, confirm that the controlled system will not be adversely affected before you
transfer the data link tables. The data links start automatically after the data link tables are trans-
ferred.
• All CPU Bus Units are restarted when routing tables are transferred from Support Software to the
CPU Unit. Confirm that the system will not be adversely affected by restarting before you transfer the
routing tables.
• Tag data links will stop between related nodes while tag data link parameters are transferred during
Controller operation. Confirm that the system will not be adversely affected before you transfer the
tag data link parameters.
EtherNet/IP Communications
• Make sure that the communications distance, number of nodes connected, and method of connec-
tion for EtherNet/IP are within specifications.
Do not connect EtherNet/IP communications to EtherCAT or other networks. An overload may cause
the network to fail or malfunction.
• All related EtherNet/IP nodes are reset when you transfer settings for the built-in EtherNet/IP port
(including IP addresses and tag data links settings). The settings can only be enabled after the reset.
Confirm that the system will not be adversely affected by resetting nodes before you transfer the set-
tings.
• If EtherNet/IP tag data links (cyclic communications) are used with a repeating hub, the communica-
tions load on the network will increase. This will increase collisions and may prevent stable communi-
cations. Do not use repeating hubs on networks where tag data links are used. Use an Ethernet
switch instead.
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NJ-series CPU Unit Hardware User's Manual (W500)