Connecting The Drives - Siemens SIMATIC S7-200 System Manual

11.4

Connecting the Drives

The standard PROFIBUS cable and connectors can be used to connect the CPU
to the MicroMaster drive. See Network Connectors in Chapter 7 for more
information. See Figure 11-8 for the proper cable bias and termination of the
interconnecting cable.
Caution
!
Interconnecting equipment with different reference potentials can cause unwanted
currents to flow through the interconnecting cable.
These unwanted currents can cause communication errors or can damage
equipment.
Be sure all equipment that you are about to connect with a communication cable
either shares a common circuit reference or is isolated to prevent unwanted
current flows. See "Grounding and Circuit Reference Point for Using Isolated
Circuits" in Section 2.3.
The shield must be tied to chassis ground or terminal 1 on the 9-pin connector. It
is recommended that you tie terminal 2-0V on the MicroMaster drive to chassis
ground.
Switch position = On
Terminated and biased
Network
connector with
programming
port
Cable must be
terminated and biased
at both ends.
TxD/RxD +
TxD/RxD -
Cable shield
Switch position = On
Terminated and biased
Figure 11-8
S7-200 Programmable Controller System Manual
A5E00066097-02
Using USS Protocol Instructions to Communicate with Drives
Switch position = Off
No termination or bias
On
A B A B
Ä Ä Ä
Interconnecting cable
Pin #
6
390 Ω
B
3
Network
220 Ω
A
connector
8
390 Ω
5
1
Bias and Termination of Interconnecting Cable
Switch position = On
Terminated and biased
Off On
A B A B A B A B
Ä
B
TxD/RxD +
A
TxD/RxD -
Cable shield
B
TxD/RxD +
A
TxD/RxD -
Cable shield
Switch position = Off
No termination or bias
Network
connector
Bare shielding
(~12 mm or 1/2 in.) must
contact the metal guides
of all locations.
Pin #
6
3
Network
connector
8
5
1
11-17