Westermo ODW-710-F2, Руководство пользователя

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Reconfiguration time under faulty condition
The reconfiguration time is determined by the time it takes to detect a faulty fibre seg-
ment plus the time it takes to transport an error status message through to the ODW-
710-F2 focal point unit. The time to transport an error status message to the focal
point unit is dependent on how many units the error status message has to be repeated
through and the total fibre length delay.
Delay
Optical fibre length delay
(typical) 5
m
s/km
Error detection 3
m
s
Error repeater delay 0.8
m
s
During reconfiguration data may be corrupted or lost.
Example
A system with one PROFIBUS DP master, 11slaves, 12 ODW-710-F2 units and a total
fibre length of 2 km. The worst-case reconfiguration time would be:
1. Optical fibre length delay:
The total optical fibre length delay.
2 x 5
m
s = 10
m
s
2. Error detection:
The time it takes to detect a faulty fibre segment.
Always 3
m
s.
3. Optical repeaters:
The optical repeater delay x Number of optical repeaters
(excluding the ODW-710-F2 units connected to PROFIBUS DP master and addressed
slave).
(12 – 2) x 0.8
m
s = 8
m
s.
4. The reconfiguration time is calculated by summing the delays
in item 1 to 3 above:
10
m
s + 3
m
s + 8
m
s = 21
m
s