261
Data Link I/O Response Time
Section 8-3
12,000 to 15,600 (approx.) words:
×
3
15,600 (approx.) to 20,000 words:
×
4
If there is a node with more than 3,850 send words, however, the factors
become
×
5 and
×
6.
Noise may increase I/O delays.
Minimum Data Link I/O Response Time
The minimum data link I/O response time (i.e., the time that will not delay any
processing) can be calculated as follows:
Both the input ON response time and output ON response time are consid-
ered negligible (0), but the data processing time required for data exchange
and the time required for the data transmission itself cannot be ignored, so
they are included in the total. The respective values are as follows:
Data processing time:
0.001
×
(8 + 16) + 0.1 = 0.124
≅
0.1 ms
Data Link transmission time:
The following formula is derived from the transmission speed (2 Mbits/s).
0.008
×
Number of data link words (ms)
In this case, this gives the following result.
0.008
×
(8 + 16) = 0.19
≅
0.2 ms
Note
Noise may increase I/O delays.
Input device
Program
Program
Input
Input ON response time
1 cycle
Output
Output device
Output ON response time
1 cycle
PLC at node #7
I/O refresh
Data exchange
PLC at node #1
Data link I/O response time
Data processing time
Data processing time
Data link transmission time
Cycle time of PLC at node #1
25 ms
Data processing time
1.9 ms
Data link transmission time
0.2 ms
Data processing time
0.1 ms
PLC cycle time at node #7
10 ms
Total (data link I/O response time)
37.2 ms
Summary of Contents for C200HW-CLK21
Page 3: ...iv ...
Page 9: ...x ...
Page 12: ...xiii TABLE OF CONTENTS Index 367 Revision History 373 ...
Page 13: ...xiv ...
Page 19: ...xx ...
Page 57: ...32 Application Precautions Section 1 5 Example CX Programmer Response Timeout Setting ...
Page 69: ...44 Message Service Procedure Section 2 2 ...
Page 111: ...86 Constructing Networks with Repeater Units Section 3 4 ...
Page 154: ...129 Setting Data Links Section 5 2 Device Information Setting Data Link Tables ...
Page 261: ...236 Response Codes Section 6 7 ...
Page 297: ...272 Message Delay Times Section 8 4 ...
Page 353: ...328 Handling Precautions Section 9 6 ...
Page 364: ...339 Changing the Data Link Tables with Active Data Links Section 10 2 ...
Page 365: ...340 Changing the Data Link Tables with Active Data Links Section 10 2 ...
Page 369: ...344 Standard Models Appendix A ...
Page 391: ...366 Using the Relay Terminal Block Appendix C ...
Page 397: ...372 Index ...
Page 401: ...376 Revision History ...