ABB S800 Product Manual page 123

Section 3 Technical Data and Performance
Calculation of load for AF100 with a length of max 8,500 m (9,300 yards)
Due to the organization of the Advant Fieldbus 100 scans, some constraints are
imposed on the transmissions. To guarantee message transfer etc., at least 50% of
the fieldbus load is reserved. The remaining load (up to 50%) can be used for S800
I/O station loading and other station loading.
The calculated load of Advant Fieldbus 100 must be equal to or less than 50%.
NOTE! 1 ms cycle time is not allowed.
Table 22. % of load on the Advant Fieldbus 100 by S800 I/O (8,500 m Bus Length)
Cycle
AI801
Time
AI810
AI820
(ms)
AI890
AI895
2
16.60% 11.80%
4 8.300% 5.900%
8
4.150% 2.950%
16 2.075% 1.475%
32
1.038% 0.738%
64 0.519% 0.369%
128
0.259% 0.184%
256
0.130% 0.092%
512 0.065% 0.046%
1024
0.032% 0.023%
2048 0.016% 0.012%
4096
0.008% 0.006%
(1) Readbacks increase the load depending on the cyclicity and with the same amount as the net load at the cycle time.
For Master the cycle time is 1024 which gives 0.016% more load. For MOD the cycle time is configurable.
(2) Total load = (load generated by INSCANT) + (load generated by OUTSCANT)
The total load if INSCANT is 32 ms and OUTSCANT is 64 ms is:
Total load = 1.038 + 0.369 = 1.407%
3BSE015969-600 A
AO801
AI830 AO810
AI830A AO810V2 AO820
AI835 AO890
AO895
16.60% 16.63% 11.82%
8.300% 8.332% 5.923%
4.150% 4.182% 2.973%
2.075% 2.107% 1.498%
1.038% 1.070% 0.761%
0.519% 0.551% 0.392%
0.259% 0.292% 0.207%
0.130% 0.162% 0.115%
0.065% 0.097% 0.069%
0.032% 0.065% 0.046%
0.016% 0.049% 0.035%
0.008% 0.041% 0.029%
Module Type
DI801, DI802
DI803, DI810 DO801
DI811, DI814 DO810
DI820, DI821 DO815
DI830, DI831 DO821
DI885, DI890
8.40% 8.40%
4.200% 4.200%
2.100% 2.100%
1.050% 1.050%
0.525% 0.525%
0.263% 0.263%
0.131% 0.131%
0.066% 0.066%
0.033% 0.033%
0.016% 0.016%
0.008% 0.008%
0.004% 0.004%
Advant Fieldbus 100 Load
(1) (1)

, DO802
(1) (1) (2)

DO814 , DP820
(1) (1)
DO820 , INSCANT
(1) (1)
DO890
16.60%
8.300%
4.150%
2.075%
1.038%
0.519%
0.259%
0.130%
0.065%
0.032%
0.016%
0.008%
(2)

DP820
OUT-
SCANT
11.80%
5.900%
2.950%
1.475%
0.738%
0.369%
0.184%
0.092%
0.046%
0.023%
0.012%
0.006%
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