290
I/O Response Time in Tag Data Links Section 10-3
Minimum Tag Data Link I/O Response Time
The minimum tag data link I/O response time, which occurs when there are no
processing delays, is calculated as follows.
When the baud rate is 100 Mbps, the transmission time can be calculated with
the following equation. If a network delay does not occur, just this transmis-
sion time is added.
Transmission time =
(Number of send data words × 2 + 74) × 8 × 0.00001 ms
Note The I/O response time may be longer due to noise, or other events.
Output
: I/O processing
: Data exchange
Tag data link I/O response time
(1) Input ON
response
time
(2) Network transmission delay time
(3) Output ON
response time
Input
Calcu-
lation
Calcu-
lation
PLC #1 processing
Tag data link refresh cycle
PLC #2 processing
Input device
Transmission
path
Output
device
PLC #1
PLC #2
(1) Node 1
(PLC #1) input ON response time
Input switch delay time 1.5 ms
CPU Unit cycle time of PLC #1 10.0 ms
(2) Transmission time (722 send data words) 0.121 msec
(3) Node 2
(PLC #1) output ON response time
CPU Unit cycle time of PLC #2 15.0 ms
Output relay delay time 2.0 ms
Total (tag data link I/O response time) 28.6 ms