13
6650-2212
Multidrop, one data exchange.
•
The data exchange between PROFIBUS DP master and slave via ODW-612 fibre
optic link will run from the ODW-600 units connected to PROFIBUS DP master
to the slave and the same way back to the master. The system delay is calculated by
summing the following:
1. Fibre:
The optical fibre length PROFIBUS DP master to addressed slave
delay x 2.
2. Optical repeaters:
The optical repeater delay * Number of optical repeaters
(excluding the ODW-612 units connected to PROFIBUS DP master and addressed
slave) x 2.
3. Converter electrical to fibre:
Signal processing delay x 2
(ODW-612 units connected to PROFIBUS DP master and addressed slave).
4. Converter fibre to electrical:
Signal processing delay x 2
(ODW-612 units connected to PROFIBUS DP master and addressed slave).
Example
•
Redundant ring, one data exchange between master and one slave.
One PROFIBUS DP master and 11 slaves with data rate 1.5 Mbit/s. 12 ODW-612
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
(excluding the ODW-612 units connected to PROFIBUS DP master and addressed
slave).
(12 – 2) x 1 μs = 10 μs
3. Converter electrical to fibre:
Signal processing delay x 2
(ODW-612 units connected to PROFIBUS DP master and addressed slave).
(1 tBit + 1.0 μs) x 2 = (0.7 μs + 1.0 μs) x 2 = 3.4 μs
4. Converter fibre to electrical:
Signal processing delay x 2
(ODW-612 units connected to PROFIBUS DP master and addressed slave).
0.3 μs x 2 = 0.6 μs
5. The system delay is calculated by summing the delays in item
1 to 4 above:
200 μs + 10 μs + 3.4 μs + 0.6 μs = 216 μs
AUDIN - 8, avenue de la malle - 51370 Saint Brice Courcelles - Tel : 03.26.04.20.21 - Fax : 03.26.04.28.20 - Web : http: www.audin.fr - Email : info@audin.fr
