Omron NX102 series User Manual

6 Process Data Communications and SDO Communications
6-24
NJ/NX-series CPU Unit Built-in EtherCAT Port User’s Manual (W505)
The following timing chart shows an example of the timing from an execution of the SDO communi-
cations instruction to the completion of the instruction execution, based on the performance model
below.
Here, it is assumed that the program that executes the SDO communications instructions is
assigned to the primary periodic task.
Performance Model Example
 When the Task Period of the Primary Periodic Task is 4 ms or Longer
*1 The slave SDO processing time depends on the slaves. Refer to the manual for the slave.
*2 The divided period is obtained by dividing the task period of primary periodic task. If the task period of pri-
mary periodic task is equal to or more than 4 ms, the EtherCAT master sends a message communications
frame to a slave and receives a message response data from the slave, according to the divided period.
Assign 1 ms to the divided period for this calculation.
*3 Round up the calculation result in parentheses to make an integer.
Task period of primary periodic task [ms] 1
SDO response data size [byte] 512
Slave SDO processing time [ms] 1.2
Message response time [ms] 5
Minimum message response time (ms) = Task period of the task that executes SDO communications
instruction
+ (Slave SDO processing time
*1
/Divided period
*2
)
*3
× Divided
period
+ (SDO response data size/256 bytes)
*3
× Divided period
IO UPG MC
Task period
(1 ms)
Task period
(1 ms)
Task period
(1 ms)
Task period
(1 ms)
Task period
(1 ms)
Task period
(1 ms)
Execution of SDO
communications
instruction
completed.
Slave SDO processing time
IO UPG MC IO UPG MC IO UPG MC IO UPG MC IO UPG MC
Frame
sent.
SDO
request
received.
SDO response
generation
completed.
EtherCAT master captures
SDO response data from slave:
256 bytes per frame.
IO: I/O refreshing
UPG: User program execution
MC: Motion control
EtherCAT master processing
Slave SDO processing
Line delay
SDO
communications
instruction
executed.

Omron NX102 series Specifications

General

Brand	Omron
Model	NX102 series
Category	Controller
Language	English