Westermo ODW-630-F2 - Manual (Page 13)

13 6651-22651
Example
• Redundant ring, one data exchange between master and one slave.
One a master and 11 slaves with data rate 9600 bit/s dependent mode.
12 ODW-630-F2 units with a total fibre length of 40 km. A data exchange
between master and one slave.
1. Fibre: The total optical fibre ring length delay.
40 x 5 µs = 200 µs
2. Optical repeaters:
The optical repeater delay x Number of optical repeaters
(excluded the two units connected to PLC master and slave).
10 x 3.0 µs = 30 µs
3. Converter electrical to fibre:
Signal processing delay x 2
(ODW-630-F2 units connected to a master and addressed slave).
(1 t
bit
+ 0.6 µs) x 2 = (105 µs + 0.6 µs) x2 = 211 µs
4. Converter fibre to electrical:
Signal processing delay x 2
(units connected to PLC master and slave).
0.6 µs x 2 = 1.2 µs
5. The system delay is calculated by summing the delays in item 1 to 4 above:
200 µs + 30 µs + 211 µs + 1.2 µs = 442 µs