Installation and Maintenance
5.10 Configuration
SIMATIC NET PROFIBUS, Optical Link Module
Operating Instructions, 07/2008, A2B00065774O, Edition V1.5
43
Data rate
a
b
c
12 Mbps
5
1651
240
28
6 Mbps
1
951
120
24
3 Mbps
1
551
60
24
1.5 Mbps
1
351
30
24
500 Kbps
251
10
24
187.5 Kbps
171
3.75
24
93.75 Kbps
171
1.875
24
45.45 Kbps
851
0,909
24
19.2 Kbps
171
0,384
24
9.6 Kbps
171
0,192
24
Table 5-2 Constants for calculating the slot time
for DP-standard (redundant optical ring)
Data rate
a
b
c
12 Mbps
1
1651
240
28
6 Mbps
1
951
120
24
3 Mbps
1
551
60
24
1.5 Mbps
1
2011
30
24
500 Kbps
771
10
24
187.5 Kbps
771
3.75
24
93.75 Kbps
451
1.875
24
45.45 Kbps
851
0.909
24
19.2 Kbps
181
0.384
24
9.6 Kbps
171
0.192
24
Table 5-3 Constants for calculating the slot time for
DP/FMS (”universal“) and DP with S5 95U (redundant optical ring)
The slot time calculation only takes into account the optical network and the
connection of bus nodes to the OLM via a RS-485 bus segment each with a
maximum length of 20 m. Longer RS-485 bus segments are included in the
calculation by adding them to the length of the fiber-optic cables.
Note:
If the value of the slot time is configured too low, this can lead to malfunctions and
error messages on the OLM. The system LED flashes red/green.
5
With OLM/G11-1300 and OLM/G12-1300, minimum slot times must be maintained according to the following table at data
rates of 12 Mbps, 6 Mbps, 3 Mbps and 1.5 Mbps:
Data rate
Minimum slot time
12 Mbps
3800 t
Bit
6 Mbps
2000 t
Bit
3 Mbps
1000 t
Bit
1.5 Mbps
530 t
Bit
If the calculated slot time is shorter than the minimum slot time, use the minimum slot time from the table above as the
configured slot time.
