Setting The Bus Terminator - Aventics PROFIBUS DP Mode D'emploi

110 AVENTICS | PROFIBUS DP | R499050016–BDL–001–AE
Commissioning and Operation
Tab. 18: Setting options for switches S7 and S8
Switch setting
S7 S8
OFF OFF
ON ON
ON OFF
OFF ON

7.1.5 Setting the bus terminator

In order to minimize line reflections and to ensure a defined rest
level on the PROFIBUS DP transfer line, a bus terminator has to
be fitted on both ends of the transfer line.
In the bus coupler, the bus terminator has been integrated into
the device and can be defined using switches S7 and S8.
A
B
Fig. 10: S7 and S8 switches for the bus terminator
The bus terminator setting is located beneath PG fitting B
(see Figure 10).
O
Set the bus terminator with switches S7 and S8 (see Table 18).
Outgoing bus on X72
Bus terminator
(BUS OUT)
Switched off Switched on
Switched on Switched off
These settings lead to instable bus behavior!
The switches are in the OFF position when delivered, i.e. the
bus terminator is switched off.
ON OFF
X71
X72
S4 S5 S6
X10
Application
When the bus coupler is connected to
another module and does not form the
end of the transfer line.
When the bus coupler is positioned at
the end of the transfer line.
Not permissible!
S7
S8
U
Q1
U
Q2