Omron SYSMAC LINK C1000H-SLK21-V1 System Manual page 78

Data Link Characteristics
Automatic Generation
Manual Generation
3.Example Calculations
64
The communications cycle time can be set either automatically (the default) or
controlled externally.
When data link tables have been generated automatically, the communications
time will be as follows for systems using coaxial cable:
No. of nodes
LR and DM Areas
2 19 ms
4 19 ms
8 19 ms
16 19 ms
The communications time will be as follows for systems using optical fiber cable.
No. of nodes
LR and DM Areas
2 21 ms
4 22 ms
8 22 ms
16 22 ms
When data link tables have been generated manually, the communications
cycle time can be set to a constant value or generated automatically.
The communications cycle time can be set as a constant from 5 to 255 ms in
increments of 1 ms via the SSS/CVSS to eliminate variations caused by noise or
other factors. When the communications cycle time is not set as a constant, it will
be generated automatically according to the equations below. Round the result
of the calculation to the nearest millisecond.
Communications cycle time (coaxial cable systems) =
Maximum node number × 85 ms + maximum number of frames × 654 ms
+ number of polled units × 750 ms + number of Link Units × 56 ms
+ total number of words × 10 ms + 1.322 ms
Communications cycle time (optical fiber cable systems) =
maximum node number × 111.5 ms + maximum number of frames × 770 ms
+ number of polled units × 750 ms + number of Link Units × 56 ms
+ total number of words × 10 ms + 1.322 ms
Note The present and maximum values of the communications cycle time can be
monitored from a SSS/CVSS.
The examples below calculate the communications cycle time for both coaxial
and optical fiber cable with the following characteristics:
Maximum node number:
Maximum number of frames:
Number of polled units:
Number of Link Units
Total number of words
Communications cycle time (coaxial cable systems) =
62 × 85 ms + 10 × 654 ms + 4 × 750 ms + 32 × 56 ms + 2000 × 10 ms + 1.322 ms
= 37.924 ms (38 ms after rounding)
Communications cycle time (optical fiber cable systems) =
62 × 111.5 ms + 10 × 770 ms + 4 × 750 ms + 32 × 56 ms + 2000 × 10 ms + 1.322 ms
= 40.727 ms (41 ms after rounding)
Data link area
LR Area only
17 ms
17 ms
18 ms
18 ms
Data link area
LR Area only
20 ms
20 ms
21 ms
21 ms
. . . . . . 62
. . 10
. . . . . . . 4
. . . . . . . . 32
. . . . . . . 2000
Section 5-10
DM Area only
18 ms
18 ms
18 ms
19 ms
DM Area only
21 ms
21 ms
21 ms
22 ms