Influence On Cycle Time; Calculating The Data Link I/O Response Time - Omron CS1W-FLN22 Operation Manual

Influence on Cycle Time

8-3 Influence on Cycle Time
Note
8-4

Calculating the Data Link I/O Response Time

Receiving PLC B Data Link Area (Sum of Local Node Setup Area and Other Node Setup Area):
7,677 Words Max.
Receiving PLC B Data Link Area (Sum of Local Node Setup Area and Other Node Setup Area):
More than 7,677 Words
136
The time required by the FL-net Unit to exchange data with the CPU Unit is
shown below. Use the value obtained from this equation to calculate the
approximate cycle time of the CPU Unit.
Approximate data processing time =
0.3 + Number of data link words × 0.0011 (ms)
(The number of data link words: The number of data link words sent and
received by the corresponding node).
1. The value obtained from this equation is for a single FL-net Unit.
2. Add the event execution time when executing message services.
The FL-net Unit I/O response time indicates the delay until data from a speci-
fied node is detected by another node on the same network. The method
used to calculate I/O response time depends on the amount of data being
exchanged between the FL-net Unit and the PLC (sum of the local node setup
area and other node setup area).
Data set
Sending PLC A
cycle time
(1)
Communications cycle time
Receiving PLC B
cycle time
1. After setting data in the data link area (local node setup area), the FL-net
Unit requires up to one cycle until it can read the data.
2. Up to one communications cycle and the token holding time is required un-
til the data from the local node setup area is sent on the FL-net communi-
cations line (i.e., until the token from the local node is held).
3. Up to one communications cycle is required until the data link data re-
ceived from the remote node is reflected in the PLC's data link area (for up
to 7,677 words of data link data (local data setup area + other node setup
area)).
4. Up to two cycles are required to refresh data sent across two CPU Unit cy-
cles when the data link data (local data setup area + other node setup ar-
ea) exceeds 7,677 words.
Data link I/O response time =
Sending PLC A cycle time + Communications cycle time
+ Token holding time + Receiving PLC B cycle time
Data link I/O response time =
Sending PLC A cycle time + Communications cycle time
+ Token holding time + Receiving PLC B cycle time × 2
(2)
(3) (4)
Section 8-3