Eaton Micro Panel XV-102, Руководство по эксплуатации

Страница: 42 / 70

5 Installation
5.3 Interfaces
42
MICRO PANEL XV-152
12/2011 MN04802006Z-EN www.eaton.com

The maximum baud rate depends on the cable length:
Tab. 22 Relationship of cable length / baud rate (for cables compliant with cable type A of the Profibus standard IEC/EN 61158
and IEC/EN 61784)
Profibus topology

A bus segment can connect up to 32 bus stations.

Several bus segments can be linked via repeaters (bidirectional amplifiers). Refer to the documen-
tation of the repeater manufacturer for further information.

Only use bus terminal connectors that are specified for use in the Profibus network. They hold both
bus cables on a bus station and ensure a low impedance connection of the cable shield to the
shield reference potential of the bus station. These bus terminal connectors contain the Profibus
cable termination that can be switched on as required.

A bus segment must be provided with cable termination at both ends. The termination is passive
and is fed from the bus station. It ensures a defined idle signal on the bus when no bus station is
transmitting. These bus terminations should be implemented externally in the connector casing
according to the Profibus standard (they can also be implemented with the bus terminating
connector described above).
Cable length Max. baud rate
200 m 1500 Kbit/s
400 m 500 Kbit/s
1000 m 187.5 Kbit/s
1200 m ≤ 93.75 Kbit/s

When preparing the cables, ensure that there is a low-resistance connection between
the cable shield and the connector casing (
→
Chapter 5.3.2,  25).

The maximum cable length can be increased by using repeaters. Refer to the documen-
tation of the repeater manufacturer for further information.
Fig. 20 Bus segment with four bus stations


The bus segment must be terminated at both ends.

No more than two terminations must be provided on each bus segment.

At least one of the two terminations must be fed by the bus station.

Transmission faults can occur if operation is carried out without the correct termina-
tion on the Profibus network.
1
2
3
6
7
5
4
8
9
390
390
1
2
3
6
7
5
4
8
9
1
2
3
6
7
5
4
8
9
1
2
3
6
7
5
4
8
9
M5EXT
(GND)
A
B
M5EXT
(GND)
A
B
M5EXT
(GND)
A
B
M5EXT
(GND)
A
B
M5EXT
(GND)
A
B
M5EXT
(GND)
A
B
220
220
390
390