Omron SYSMAC CJ1W-EIP21, Operation Manuals

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12 Communications Performance and Communications Load
12-26
CJ-series EtherNet/IP Units Operation Manual for NJ-series CPU Unit (W495)
(2) Send Data Processing Time
This is the time until the variables in the CPU Unit are transferred to the EtherNet/IP Unit. Data is
transferred during task processing. Therefore, the time required for send data processing is the
same as the task period. If the data that is transferred is larger than the amount of data that can be
sent during a single task (as set in the variable access time for the task), the data is transferred over
multiple task periods. Therefore, add (task period
×
the number of transfers) to the time required. For
details on how to determine the time required to send data, refer to 12-3-2 EtherNet/IP Unit Data
Processing Time.
(3) Packet Interval (RPI)
This is the communications refresh period set for each connection using the Network Configurator.
(4) Network Transmission Delay Time
The transmission delay on an Ethernet line is 50
μ
s or less. This delay time can be ignored.
(5) Receive Data Processing Time
This is the time required to transfer data received on the EtherNet/IP Unit to a variable in the CPU
Unit. Data is received during task processing. Therefore, the time required for receive data process-
ing is the same as the task period. If the data that is transferred is larger than the amount of data
that can be received during a single task (as set in the variable access time for the task), the data is
transferred over multiple task periods. Therefore, add (task period
×
the number of transfers) to the
time required. For details on how to determine the time required to receive data, refer to 12-3-2 Eth-
erNet/IP Unit Data Processing Time. Data is transferred once in each task period. Therefore, if data
transfer has ended in the task period in which data is received, the start of transmission for received
data will be delayed by one Controller task period.
Additional Information
The total amount of data transferred increases if there are connections with multiple nodes, and
the data that is transferred may exceed the amount that can be processed in a single transfer. In
this case, the number of data transfers increases.
(6) Output ON Response Time
This is the delay time for the external output device from when the Controller specified turning ON
the output until the output is actually turned ON.
Output ON response time = Output device delay time + Task period
Additional Information
The I/O response time may be longer due to noise, or other events.