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Message Service Transmission Delay Section 10-5
Note CJ2 CPU Units support only Normal Mode.
For details, refer to the CPU Unit’s Operation Manual.
CPU Bus Unit Service
Cycle (Local Node, 2)
The following table shows the CPU Bus Unit service cycle, which depends on
the CPU Unit’s CPU processing mode setting.
Note CJ2 CPU Units support only Normal Mode.
For details, refer to the CPU Unit’s Operation Manual.
CPU Bus Unit Service
Processing Time (Local
Node, 2)
The following table shows the CPU Bus Unit service processing time, which
depends on the CPU Unit’s CPU processing mode setting.
Note CJ2 CPU Units support only Normal Mode.
For details, refer to the CPU Unit’s Operation Manual.
Note Depending on the actual operating environment, the transmission time may
be longer than the one calculated with the equations given here. The following
factors can cause longer transmission times: other traffic on the network, win-
dow sizes of network nodes, other traffic at the EtherNet/IP Unit or built-in Eth-
erNet/IP port itself (e.g., simultaneous tag data link communications), and the
system configuration.
Parallel processing with syn-
chronous memory access
4% of CPU Unit cycle time
Parallel processing with asyn-
chronous memory access
1 ms max.
CPU execution mode Processing time details
CPU execution mode Processing time details
Normal Mode (See note.) One CPU Unit cycle time
Priority peripheral servicing EtherNet/IP Unit or
built-in EtherNet/IP
port is given prior-
ity.
Time slice instruction execution
time
EtherNet/IP Unit or
built-in EtherNet/IP
port is not given
priority.
One CPU Unit cycle time
Parallel processing with syn-
chronous memory access
One CPU Unit cycle time
Parallel processing with asyn-
chronous memory access
0.2 ms + peripheral servicing time (1 ms max. for
peripheral servicing of each Special I/O Unit, CPU
Bus Unit, peripheral port, RS-232C port, and Inner
Board)
CPU execution mode Processing time details
Normal Mode (See note.) 4% of CPU Unit cycle time
(10% for CJ2 CPU Units)
Priority peripheral servicing EtherNet/IP Unit or
built-in EtherNet/IP
port is given prior-
ity.
Time slice peripheral servicing
execution time
EtherNet/IP Unit or
built-in EtherNet/IP
port is not given
priority.
Set peripheral servicing time
(Default: 4% of CPU Unit cycle
time)
Parallel processing with syn-
chronous memory access
4% of CPU Unit cycle time
Parallel processing with asyn-
chronous memory access
1 ms max.