Siemens SIMATIC S7-200 - Bias and Termination of Interconnecting Cable; Cable for a Profibus Network; General Specifications for a Profibus Network Cable

Setting Up Communications Hardware and Network Communications
7-34
S7-200 Programmable Controller System Manual
A5E00066097-02
Ä
Ä
ABAB
ÄÄ
ÄÄ
Ä
Ä
ABAB
On On
Ä
Ä
ABAB
Off
Switch position = On
Terminated and biased
Switch position = Off
No termination or bias
Switch position = On
Terminated and biased
Cable must be
terminated and biased
at both ends.
Interconnecting cable
390 Ω
220 Ω
390 Ω
B
A
TxD/RxD +
TxD/RxD -
Cable shield
6
3
8
5
1
Network
connector
Pin #
B
A
TxD/RxD +
TxD/RxD -
Cable shield
Network
connector
A
B
Switch position = Off
No termination or bias
TxD/RxD +
TxD/RxD -
Cable shield
Switch position = On
Terminated and biased
Bare shielding
(~12 mm or 1/2 in.) must
contact the metal guides
of all locations.
6
3
8
5
1
Pin #
Network
connector with
programming
port
Network
connector
Figure 7-24 Bias and Termination of Interconnecting Cable
Cable for a PROFIBUS Network
Table 7-6 lists the general specifications for a PROFIBUS network cable. See
Appendix E for the Siemens order number for PROFIBUS cable meeting these
requirements.
Table 7-6 General Specifications for a PROFIBUS Network Cable
General Features
Specification
Type Shielded, twisted pair
Conductor cross section 24 AWG (0.22 mm
2
) or larger
Cable capacitance < 60 pF/m
Nominal impedance 100 Ω to 120 Ω