ABB S800 Product Manual page 145

Section 3 Technical Data and Performance
Calculation of Maximum Fiber length for TB826
The maximum signal delay in a configuration is calculated using Optical Media
Converter. This is calculated using the signal path from the controller to the point in
the configuration that has the longest delay. The maximum delay in a optical
ModuleBus configuration must be  100
S800 I/O HI).
The delay values in
optical ModuleBus configuration.
Opto-to-opto delay in TB826
Opto-to-opto delay in TB820
Opto-to-electrical delay in TB820
Opto-to-opto delay in TB840
Opto-to-electrical delay in TB840
Delay in optical fiber
(1) Notice that the delays in the table is the sum of the communication delay in both directions, i.e.
(2) Total fiber length = total local fiber length + field fiber length
3BSE015969-600 A
Table 30
Table 30. Delay Values Optical ModuleBus Components
(1)(2)
(delay of master frame) + (delay of slave frame).
Calculation of Maximum Distance of an Optical
µ
s (less than 250
can be used to calculate the maximum delay in an
(1)
(1)
(1)
(1)
(1)
s for 
µ
2.0 µs
4.0 µs
6.5 µs
2.0 µs
5.5 µs
(0.01 x length) µs
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