Omron CS CJ1W-ETN21 Operation Manual page 217

Maximum Transmission Delays: Writing/Reading to CPU Unit
Transmission Processing
(Response)
Note
Read Command Delay
Time
Transmission Delay
Reception Processing
(Command)
CPU Bus Unit Service
Cycle
CPU execution mode
Parallel processing with
synchronous memory
access
Parallel processing with
asynchronous memory
access
For details, refer to the CPU Unit operation manual.
0.704 ms
The actual operating environment can cause transmission delays larger than
those calculated with the methods given here. Among the causes of longer
delays are the following: traffic on the network, window sizes at network
nodes, traffic through the Ethernet Unit (e.g., simultaneous socket servicing
and FTP server communications, etc.), and the system configuration.
Maximum transmission delay =
Transmission processing time (remote node)
+ Transmission delays
+ Reception processing time (command) (local node)
+ CPU Bus Unit service cycle (local node)
+ CPU Bus Unit service processing time (local node)
+ Transmission processing time (response) (local node)
+ Transmission delays
+ Reception processing time (remote node)
The transmission delay time depends on the baud rate set for the Ethernet
Unit, as shown in the following table. (Additional delays may depending on
devices, such as hubs, in the network configuration.)
Baud rate
100Base-TX Command
Response
10Base-T Command
Response
0.704 ms
The processing time will be as follows, depending on the CPU processing
mode settings at the CPU Unit.
CPU execution mode
Normal Mode
Priority peripheral ser-
vicing
Parallel processing with
synchronous memory
access
Parallel processing with
asynchronous memory
access
Processing time considerations
Set time for peripheral servicing
(Default: 4% of CPU Unit cycle time)
1 ms max.
Delay time
0.0118 ms
Number of words sent
0.0157 ms
Number of words sent
Processing time considerations
CPU Unit cycle time
Ethernet Unit is given prior-
ity.
Ethernet Unit is not given
priority.
CPU Unit cycle time
0.2 ms + peripheral servicing time (1 ms max. of peripheral
servicing time for each Special I/O Unit, CPU Bus Unit,
peripheral port, RS-232C port, and Inner Board)
Section 7-5
×
0.0013 + 0.0118 ms
×
0.0019 + 0.0157 ms
Time slice instruction execu-
tion time
CPU Unit cycle time
193