Omron CJ1W-EIP21 用户手册

Observe the following precautions when writing application 
programs:

• Maintain the simultaneity of data in connection-units between 

the PLC and EtherNet/IP Unit or built-in EtherNet/IP port.

• If another company's device is being used, refer to that 

device's user's manual for details.

• When received data is used in the ladder program, use the 

All Tag Data Links Operating Flag in Communications Status 
1, or the Target Node PLC Operating Flag as a condition. If 
the Target Node PLC Operating Flag is used, the PLC status 
must be included in tag sets of both the sending and receiv-
ing nodes.

• If the Output OFF function (Output Inhibit) is enabled in the 

output (produce) tag settings, all of the output data will be 
OFF if a fatal error occurs in the CPU Unit or the Output OFF 
Bit is turned ON. Check the status of the output (producer) 
PLC.

• Check whether the baud rate is set to 10 Mbps, or a 10M or 

100M repeater hub is being used. The tag data link perfor-
mance is based on the use of switching hubs. The bandwidth 
listed in the specifications (CJ2M: 3,000 pps, other CPU 
Units: 6,000 pps) is achieved when the Unit auto-negotiates 
to full-duplex at 100 Mbps.

• Refer to 14-1 Checking Status with the Network Configurator 

for details on checking the error counters on the Monitor 
Device Window’s Ethernet Information Tab Page. The error 
and discarded packet counters indicate problems such as 
noise in the communications path, the use of substandard 
cables, damaged cables/connectors, loose connectors, 
abnormally high communications load, or incorrect wiring 
(loops) in the switching hub wiring.

• Contact the switching hub manufacturer to determine 

whether there are any problems with the transfer capacity of 
the switching hubs in the communications path. If switching 
hubs are arranged in a cascade connection, there may be a 
heavy load concentrated at a mid-level switching hub. In the 
EtherNet/IP Unit or built-in EtherNet/IP port itself, processing 
is performed with a higher priority than message communi-
cations, so specifications provide for a 3,000 pps bandwidth 
for the CJ2M and a 6,000 pps bandwidth for other CPU Units 
in tag data link performance only.

• Refer to 14-1 Checking Status with the Network Configurator 

for details on checking the connection status on the Monitor 
Device Window’s Connection Tab Page. Eliminate any errors, 
which can be identified in the tables in 14-3 Connection Sta-
tus Codes and Error Processing.