Built-In Ethernet/Ip Port Data Processing Time - Omron Sysmac NJ-series User Manual

14-3-2 Built-in EtherNet/IP Port Data Processing Time

This section describes the data processing time required to transfer data between the built-in Ether-
Net/IP port and the CPU Unit.
Data Processing Time Overview
The time required for data processing consists of the following three elements.
1. Variable Access Time
First, calculate the time required to transfer tag data (or the time required to access variables).
This calculation is performed for each task. Therefore, if the same refreshing task is set for multiple
tag sets, calculate the total time required for all tags in the tag sets.
Use the following equation to calculate the variable access time.
Variable access time [μs] = Total size of variables [bytes] × a + Number of variables × b
Number of accesses: Number of tag sets
a to d: Constant values as given below
CPU Unit model
NX701-
NX1P2-
NJ501-
NJ301-
NJ101-
*1 The value is 0.58 for a CPU Unit with unit version 1.02 or earlier.
*2 The value is 0.0009 for a CPU Unit with unit version 1.02 or earlier.
*3 The value is 1.03 for a CPU Unit with unit version 1.02 or earlier.
2. Number of Data Transfers
Tag data is transferred as a part of task processing.
If the time required to process the data transfer is greater than the "variable access time"
cannot be sent entirely in one task period and is sent separately instead.
Number of data transfers = "Time required to send the data entirely"
*1 This is the variable access time as calculated in step 1 above.
*2 The "variable access time" refers to the maximum processing time for accessing variables. Set the time for
each task on the Task Setup Display, which is displayed by selecting Configurations and Setup - Task Setup
in the Sysmac Studio.
Precautions for Correct Use Precautions for Correct Use
The maximum number of tag data link words that can be transferred through the built-in Ether-
Net/IP port is 184,832 words on an NX701 CPU Unit (total of 369,664 words with two ports), or
9,600 words on an NJ-series CPU Unit and an NX1P2 CPU Unit. If the number of tag data link
words exceeds the number of words that can be exchanged with the CPU Unit at one time, the
data is divided and transferred in multiple data exchanges.
NJ/NX-series CPU Unit Built-in EtherNet/IP Port User's Manual (W506)
14 Communications Performance and Communications Load
+ Number of accesses × c + d
a
0.0005 0.033
0.0040 0.240
0.0010 *1
0.490
*2 *3
0.0015 0.560
0.0015 0.560
÷ "Variable access time"
Constant value [μs]
b c
2.67
3.27
1.41
2.15
3.83
*1
*2
set for the task
14
d
7.22
25.21
6.68
7.52
7.52
*2
, the data
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