Omron SYSMAC CS1W-CLK13 Operation Manual page 250

Data Link I/O Response Time
CVM1, CV-series, CS-series PLCs Under Synchronous Operation
Maximum Data Link I/O Response Time
1,2,3...
Input
Input ON delay
There are three points shown in the diagram above where processing is
delayed, increasing the data link I/O response time.
1. The input arrives in the PLC just after I/O refreshing, causing a delay of up
to one cycle before the input is read into the PLC.
2. Data exchange occurs just after the PLC at node #1 passes the token that
makes it the polling node, causing a delay of up to one communications cy-
cle time before the data is transferred in data link processing.
3. At node #7, data from the previous data exchange is still being transferred,
causing a delay of up to one cycle before the input is read into the PLC. (If
the cycle time at node #7 is longer than the communications cycle time, the
processing will be delayed for two cycles.) Also, if the total number of data
link words exceeds the maximum number for a single exchange, the data
exchange will be divided up and there may be a delay of one to two addi-
tional cycles.
The maximum number of words that can be exchanged in a single data ex-
change is approx. 7,800 words for CS-series PLCs and approx. 3,700
words for CVM1 and CV-series PLCs.
The equation for the maximum data link I/O response time is as follows:
Input ON response time
Cycle time of PLC at node #1 × 2
Communications cycle time × 2
PLC cycle time at node #7 × 2
Output ON response time
Total (data link I/O response time)
Note The PLC cycle time when data link words exceed 12,000 using a CS-series
Controller Link Unit with unit version 1.2 or later is calculated as follows.
12,000 to 15,600 (approx.) words: × 3
15,600 (approx.) to 20,000 words: × 4
Input device
1 cycle
PLC at node #1
Program
Communications
cycle time
PLC at node #7
Output device
Data link I/O response time
1.5 ms
25 ms × 2
22 ms × 2
10 ms × 2 (See note.)
15 ms
130.5 ms
Section 9-3
I/O refresh
Data exchange
Data link transmission
1 cycle
Program
Output ON delay
Output
227