Omron NX-ECC201 - Message Response Time

12 - 23
12 Communications Performance
NX-series EtherCAT Coupler Unit User’s Manual (W519)
12-2 Message Response Time
12
12-2-2 Message Response Time
• Tcycle: Task period of the primary periodic task in the CPU Unit
• Ts-resp: Slave message response time
*1. If Tcycle divides Ts-resp evenly, there is no need to add 1.
*2. If 256 divides the data byte size of the message response evenly, there is no need to add 1.
 Slave Message Response Time: Ts-resp
This is the time from when the message request is received until the EtherCAT Slave Terminal com-
pletes generating the response.
(a) Reading and Writing SDO Data
The destination is the EtherCAT Coupler Unit and the value is as follows:
Ts-resp = 30 to 80 μs
(b) Reading and Writing NX Objects
If the destination is the EtherCAT Coupler Unit, the value is as follows:
Ts-resp = 400 to 1,000 μs
If the destination is an NX Unit, the value is as follows:
Ts-resp = 450 to 7,000 μs
Calculating the Message Response Time
Message response time =
Tcycle + {((Ts-resp ÷Tcycle) + 1
*1
) × Tcycle}
+ {((Data byte size of response message ÷256)
+ 1
*2
) × Tcy cl e} + Tc y cl e
IO UPG IO
EtherCAT Coupler Unit #1
NX Unit number 1
NX Unit number 2
NX Unit number 3
IO
Line delay
NJ-series
CPU Unit
MC UPG MC UPG MC IO UPG MC
Message communications instruction executed.
System services
EtherCAT Coupler Unit #2
NX Unit number 1
NX Unit number 2
I/O: I/O refreshing
UPG: User program execution
MC: Motion control
Primary period
Tcycle
Primary period
Tcycle
Primary period
Tcycle
Primary period
Tcycle
Frame sent.
Response data
sent.
Request received.
Slave message response time: Ts-resp
Destination:
EtherCAT
Coupler Unit
Destination:
NX Unit
Request received.
Response generated.
Request received.
Response
generation
completed.
Response
generation
completed.