Omron NJ Series User Manual

A-15
Appendices
NJ-series CPU Unit Software User’s Manual (W501)
A-2 Calculating Guidelines for the Real Processing Times of Tasks
App
A-2-1 Calculating the Average Real Processing Times of Tasks
 CJ-series Unit Processing Time
Use the following formula for the CJ-series Unit processing time.
 (I/O refresh time for each CJ-series Unit  Number of Units) - 230 [s]
In the above formula,  represents the total processing time for all CJ-series Units.
If the result that is calculated from the above formula is a negative number, the CJ-series Unit pro-
cessing time is regarded as 0 s.
The method for calculating the I/O refresh time for each CJ-series Unit is provided later.
If any of the following CJ-series Units is used, add 230 s to the result that is calculated from the
above formula, regardless of the number of Units.
• CJ1W-PH41U Analog Input Unit with Universal Inputs
• CJ1W-AD04U Analog Input Unit with Universal Inputs
• CJ1W-PDC15 Analog Input Unit with Universal Inputs
• CJ1W-V680C11 ID Sensor Unit
• CJ1W-V680C12 ID Sensor Unit
• CJ1W-CRM21 CompoNet Master Unit
The I/O refresh time for EtherCAT slaves is found by individually calculating the I/O refresh time for
each EtherCAT slave and then adding them together.
The I/O refresh time for each EtherCAT slave is calculated from the input processing data size and out-
put processing data size.
Refer to the manuals for the specific EtherCAT slaves for their input processing data size and output
processing data size.
The formula for calculating the I/O refresh time for an EtherCAT slave is as follows:
I/O refresh time = Tout  Dout + Tin  Din + Tref  Dinout + 1.24 [s]
The values of the output processing time, input processing time, and refresh processing time in the
above formula are fixed. They are determined by the model of the CPU Unit as given in the following
table.
I/O Refresh Time for EtherCAT Slaves
Tout : Output processing time per byte
Dout : Output processing data size in bytes
Tin : Input processing time per byte
Din : Input processing data size in bytes
Tref : Refresh processing time per byte
Dinout : Larger of the input and output process data size in bytes
CPU Unit
Tout: Output pro-
cessing time per
byte [s]
Tin: Input process-
ing time per byte [s]
Tref: Refresh processing
time per byte [s]
NJ501- 0.004 0.011 0.082
NJ301- 0.005 0.013 0.082

Omron NJ Series Specifications

General

Program Capacity	Up to 128 MB
SD Card Slot	Yes
Power Supply Voltage	24 VDC
Motion Control	Yes
USB Ports	1
Operating Temperature	0°C to 55°C
Communication Interfaces	Ethernet/IP, EtherCAT, USB
Safety Function	Optional
Storage Temperature	-20°C to 75°C
Communication Ports	USB
Dimensions	Varies by model
Weight	Varies by model