Connecting And Setting Up The Micromaster Series 3 Drive - Siemens Simatic S7-200 System Manual

S7-200 Programmable Controller System Manual

Connecting and Setting Up the MicroMaster Series 3 Drive

Connecting the MicroMaster 3 Drive
You can use the standard PROFIBUS cable and connectors to connect the S7-200 to the MicroMaster
Series 3 (MM3) drive. See Figure 11-5 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 communications errors or damage equipment.
Be sure all equipment that you are about to connect with a communications cable either shares a
common circuit reference or is isolated to prevent unwanted current flows.
The shield must be tied to chassis ground or pin 1 on the 9-pin connector. It is recommended that you
tie wiring terminal 2–0V on the MicroMaster drive to chassis ground.
Cable must be terminated
and biased at both ends.
11
TxD/RxD +
TxD/RxD -
Cable shield
Figure 11-5
324
Switch position = On
Terminated and biased
A B A B
Ó
Ó
Switch position = On: Terminated and biased
Pin #
6
390 Ω
B
3
220 Ω
A
8
390 Ω
5
1
Bias and Termination of the Network Cable
Switch position = Off
No termination or bias
On Off
A B A B
Ó Ó
Ó Ó
Bare shielding: approximately 12 mm (1/2 in.) must contact the
metal guides of all locations.
Switch position = Off: No termination or bias
TxD/RxD +
TxD/RxD -
Cable shield
TxD/RxD +
Network
connector
TxD/RxD -
Cable shield
Switch position = On
Terminated and biased
On
A B A B
Ó
Ó
B
Pin #
A
6
B
3
Network
A
connector
8
5
1