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Appendix C
PC Link System I/O Response Time
Calculating the PC Link Transmission Time
Calculating the PC Link Cycle Time
The following diagram shows the PC Link’s cycle time.
PC Link cycle time = (T
N
×
Total number of PLCs in PC Link) + 10 ms
T
N
= Transmission time/Node
Example Calculation:
When there are 128 Link Relay bits/Unit and 8 Units are connected, T
N
= 2.8 ms.
PC Link cycle time = 2.8
×
8 + 10 ms = 32.4 ms
Calculating the Polling Sequence Processing Time
The link polling sequence, which is directed to nodes that have not yet joined the PC Link, is sent once every
256 PC Link cycles. Consequently the polling sequence cycle is 256
×
one PC Link cycle.
Polling sequence processing time = 15 ms
×
(n
−
m)
(n: max. number of connectable Units; m: number of Units joined into PC Link)
Minimum Transmission Time
Minimum transmission time = T
N
+ 10 ms
To determine the value of T
N
, refer to the table above.
T
N
Polling Unit
(Master)
Slave
Polling
Node 1
Slave data transfer
Processing time when data
transfer is completed = 10 ms
10 ms
Processing
One cycle's transmission time
Send
Receive
Node 2
Node n
Number of Link bits/Unit
32
64
128
256
512
T
N
(ms)
2.2
2.5
2.8
3.8
5.8
PC Link
cycle
256 PC Link cycles
Polling
sequence
processing
Polling
sequence
processing
Содержание CVM1 Series
Страница 1: ...Cat No W434 E1 01 SYSMAC CVM1 CV Series CVM1 LK401 PC Link Unit This manual is PDF file only...
Страница 2: ...CVM1 LK401 PC Link Unit Operation Manual Produced July 2004...
Страница 3: ...iv...
Страница 5: ...vi...
Страница 41: ...26 Differences from Earlier PC Link Units Section 2 6...
Страница 77: ...62 Replacement Checklists Section 3 6...
Страница 95: ...80 Link Adapter Specifications Appendix B...
Страница 101: ...86 PC Link System I O Response Time Appendix C...
Страница 103: ...88 PC Link Settings and Status Areas Appendix D...
Страница 105: ...Revision History 90...