Omron Sysmac NJ Series User Manual page 158

6 Process Data Communications and SDO Communications
5. The slave receives the send frame of the process data from the EtherCAT master in the scheduled
trigger timing, and outputs data to relays and other output devices.
Calculation Formula for Maximum I/O Response Time
The maximum I/O response time is calculated for each periodic task of the CPU Unit in which I/O is
refreshed for EtherCAT slaves.
The formula for calculating the maximum I/O response time is as follows:
Maximum I/O response time =
Precautions for Correct Use
The values that are found in the above formula are guidelines instead of guaranteed values.
You must use a physical device to check the performance before the actual operation.
The following describes how to find each element value in the formula.
 Task Period of Periodic Task
This indicates the task period of the primary periodic task or the priority-5 periodic task. The priori-
ty-5 periodic task is applicable only when you use an NX701 CPU Unit.
 Transmission Delay Time
The following methods are provided to calculate the transmission delay times for the CPU Unit and
the periodic tasks in which I/O is refreshed.
Precautions for Correct Use
The calculation of the transmission delay times described below assume that OMRON slaves
are used with recommended cables.
CPU Unit
NX701
NX102 and NX1P2
NJ-series
1. Calculation with the Sysmac Studio
You can use the Sysmac Studio to display the transmission delay time for the EtherCAT master.
Refer to Displaying Transmission Delay Time for EtherCAT Master with the Sysmac Studio on
page 6-14 for details on this display method.
2. Calculation by a formula
6-12
Task period of periodic task (= process data communications cycle) × 2
+ Slave input response time + Slave output response time
+ Transmission delay time + Transmission jitter
Periodic task of the CPU Unit in
which I/O is refreshed
Primary periodic task
Priority-5 periodic task
Primary periodic task
NJ/NX-series CPU Unit Built-in EtherCAT Port User's Manual (W505)
Calculation method
•
Calculation with the Sysmac
Studio
•
Calculation by a formula
Calculation with the Sysmac Stu-
dio
•
Calculation with the Sysmac
Studio
•
Calculation by a formula
Calculation by a formula