Omron NJ101-10 Series, User Manual

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*3. Round up the calculation result in parentheses to make an integer.
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 as-
signed to the primary periodic task.
Performance Model Example
Task period of primary periodic task [ms] 4
Divided period [ms] 1
SDO response data size [byte] 512
Slave SDO processing time [ms] 1.2
Message response time [ms] 8
Task period (4 ms)
UPG
Divided period
(1 ms)
SDO communications
instruction executed.
Frame
sent.
SDO
request
received. SDO response
generation
completed.
Task period (4 ms)
UPG
Task period (4 ms)
EtherCAT master processing
UPG: User program execution
Slave SDO processing
Execution of SDO
communications
instruction
completed.
Line delay
EtherCAT master captures
SDO response data from slave:
256 bytes per frame.
Slave SDO
processing time
NJ-series CPU Units
The calculation formula for the minimum message response time is given below.
Minimum message response time (ms) =
Task period of the task that executes the SDO communications instruction
+ (Slave SDO processing time
*1
/Task period of primary periodic task)
*2
x Task period of primary periodic task
+ (SDO response data size/256 bytes)
*2
× Task period of primary periodic task
*1. The slave SDO processing time depends on the slaves. Refer to relevant manuals for each slave.
*2. Round up the calculation result in parentheses to make an integer.
The following timing chart shows an example of the timing from an execution of the SDO communica-
tions instruction to the completion of the instruction execution, based on the performance model be-
low.
Here, it is assumed that the program that executes the SDO communications instructions is assigned
to the primary periodic task.
Performance Model Example
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
6 Process Data Communications and SDO Communications
6-23
NJ/NX-series CPU Unit Built-in EtherCAT Port User's Manual (W505)
6-2
SDO Communications
6
6-2-4
Minimum Message Response T
ime for SDO Communications