Siemens SIMATIC ET 200AL, System Manual

Page: 1915 / 2255

Description
2.2 Structure of PROFIBUS networks
PROFIBUS with STEP 7 V13
18
Function Manual, 12/2014, A5E03775446-AC
Selection criteria for networking
The table below includes selection criteria for electrical and optical networking of PROFIBUS
devices:
Table 2- 3 Selection criteria for electrical and optical networking
Criteria Electrical
PROFIBUS
Optical network
with OLM
Optical network
with OBT
Transmission
medium
Shielded two-wire
line
● – –
POF – ● ●
PCF – ● ●
Glass – ● –
Distances Max. network span PROFIBUS DP:
9.6 km
PROFIBUS PA:
1.9 km
90 km 9.6 km
Between two devices up to 1 km 1) up to 15 km 2) up to 300 m 2)
Topology Bus ● – –
Linear – ● ●
Tree ● ● ●
Ring – ● ●
Transmission
protocols
DP, PA DP, PA DP
Connection of
devices by means
of
OLM – ● –
Integrated interfaces ● – ●
Bus terminal ● – ●
Bus connector ● – –
Electrical network
segments can be
connected
● ● –
● Suitable
– Not relevant for this application
1) Depending on data rate and type of service used
2) Depending on cable type used
Installation guideline for PROFIBUS networks
A PROFIBUS segment must be terminated at the start and end; passively with a connector
or actively with a bus terminating resistor.
The same principles apply to the installation of a PROFIBUS network as described in the
SIMATIC NET PROFIBUS networks
( http://support.automation.siemens.com/WW/view/en/35222591 ) manual.