Omron C200HW-CLK21 Operation Manual page 281

Data Link I/O Response Time
Input
Input device
Input ON delay
X
(1)
1,2,3...
258
1 cycle
Program
X
(2)
Communications
cycle time
PLC at node #7
Data link I/O response time
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. The data transferred in data link processing arrives at the PLC at node #7
after data exchange, so the data will not be read into the PLC until the next
data exchange, causing a delay of up to 1 to 2 cycle.
The maximum number of words that can be exchanged in a single data ex-
change is approx. 7,800 words for CS/CJ-series PLCs, approx. 3,700
words for CVM1 and CV-series PLCs, approx. 4,000 for C200HX/HG/HE
PLCs, and approx. 1,200 words for CQM1H-series PLCs.
The equation for maximum data link I/O response time is as follows:
Input ON delay
Cycle time of PLC at node #1
Communications cycle time
PLC cycle time at node #7
Output ON delay
Total (data link I/O response time)
Note If the total number of data link words is greater than the maximum number of
words that can be exchanged per data exchange, the maximum data link I/O
response time will be cycle time of PLC at node #7
In case of the CQM1H, however, the cycle time will be incremented by the
value obtained from dividing the total number of data link words by the maxi-
PLC at node #1
Controller Link Unit
transmission processing
Data link transmission
Controller Link Unit
transmission processing
X
(3)
Program
1 cycle
Output device
1.5 ms
2 15 ms
3 9.9 ms
2 (See note.) 8 ms 2 (See note.)
15 ms
92.2 ms
Section 8-3
I/O refresh
Data exchange
Output ON
delay
Output
2
3
3.