18 •
Installation
Fieldbus Dependent I/O Module
PROFIBUS DP
4.2.6 Connection of the Fieldbus Interface
The WAGO-I/O-SYSTEM 752 for PROFIBUS is provided with a 9 pole D-
SUB plug connector for interfacing to the PROFIBUS network.
1
6
7
8
9
2
3
4
5
9-pol. D-Sub-Buchse
DGND
RxD/TxD-P
RxD/TxD-N
RTS
VP
Fig. 4-14: Connection design
g1xx300d
4.2.7 Cabling of the Fieldbus Conductors
On the PROFIBUS with RS 485 transmission technology all devices are con-
nected in a line structure. The bus line comprises of a twisted and screened
pair of wires.
The fieldbus line is specified in EN 50 170 as a line type A and must provide
certain line parameters. The line type B also described in the EN 50 170 is an
old type and should no longer be used.
Parameter
Value
Wave resistance
135 ... 165
Ω
Operating capacity
< 30 pF/m
Loop resistance
110
Ω
/km
Wire diameter
*)
> 0.64 mm
Wire cross section
*)
> 0.34 mm
2
*)
The wire cross sections used must conform with connection possibilities on the bus plug.
Line type A allows maximum line lengths for a bus segment dependent upon
the transmission speed.
Transmission speed
Max. bus segment length
9.6 / 19.2 / 45.45 / 93.75
kBaud
1200 m
187.5
kBaud
1000 m
500 kBaud
400
m
1500 kBaud
200
m
3000 / 6000 / 12000
kBaud
100 m
