Example Of Calculating The Average Real Processing Time Of A Task And Setting The Task Period - Omron NJ-series User Manual

Appendices
A-2-2 Example of Calculating the Average Real Processing Time of a
Task and Setting the Task Period
Example of Calculating the Average Real Processing Times of Tasks
If you are using an NJ501- CPU Unit with a unit version of 1.02, first find the average real pro-
cessing time of the task for the following conditions. The task is the primary periodic task.
Slaves/Units that are
used
User program
Motion control pro-
cessing
 I/O Refresh Time
I/O refresh overhead time:
The I/O refresh overhead time is 60 s because the EtherCAT slaves are connected.
EtherCAT slave processing time:
The following table gives the Tout (output processing time per byte), Tin (input processing time per
byte), and Tref (refresh processing time per byte) values when an NJ501- CPU Unit is used.
Tout: Output process-
ing time per byte [s]
The following table gives the Dout (output processing data size), Din (input processing data size),
and Dinout (larger of the input and output data size) values of the GX-ID1611 (Ver. 1.1) Input Slave,
GX-OD1611 (Ver. 1.1) Output Slave, and R88D- (Ver. 2.1) Servomotors.
EtherCAT slave
GX-ID1611 (Ver. 1.1)
GX-OD1611 (Ver. 1.1)
R88D- (Ver. 2.1)
A-22
Item
EtherCAT slaves
CJ-series Units (on CPU
Rack)
Language
Standard instruction con-
figuration
Arithmetic instructions for
LREAL data
Trigonometric instructions
for LREAL data
Number of axes
Tin: Input process-
ing time per byte [s]
0.004 0.011
Dout: Output process-
ing data size in bytes
Conditions
• GX-ID1611 (Ver. 1.1) Input Slave: 1
• GX-OD1611 (Ver. 1.1) Output Slave: 1
• R88D- (Ver. 2.1) Servomotors: 4
• CJ1W-ID211 DC Input Unit: 1
• CJ1W-OD211 Transistor Output Unit: 1
• CJ1W-AD042 Analog Input Unit: 1
• CJ1W-DA021 Analog Output Unit: 1
• CJ1W-SCU42 Serial Communications Unit: 1
(Protocol macros are not used.)
Ladder diagrams
Number of instructions: 5,000
Number of instructions: 200
Number of instructions: 100
4
Tref: Refresh processing time
per byte [s]
Din: Input processing
data size in bytes
0
2
23
NJ-series CPU Unit Software User's Manual (W501)
0.082
Dinout: Larger of the
input and output data size
3 3
1 2
26 26