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14 Communications Performance and Communications Load
NJ/NX-series CPU Unit Built-in EtherNet/IP Port User’s Manual (W506)
14-3 I/O Response Time in Tag Data Links
14
14-3-4 Maximum Tag Data Link I/O Response Time
(2) Send Data Processing Time
This is the time until the variables in the CPU Unit are transferred to the built-in EtherNet/IP port.
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 14-3-2 Built-in Eth-
erNet/IP Port 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 μs or less. This delay time can be ignored.
(5) Receive Data Processing Time
This is the time required to transfer data received on the built-in EtherNet/IP port to a variable in the
CPU Unit. Data is received during task processing. Therefore, the time required for receive data pro-
cessing 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 14-3-
2 Built-in EtherNet/IP Port 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 trans-
mission for received data will be delayed by one Controller task period.
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
The I/O response time may be longer due to noise, or other events.
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