Siemens SIMATIC NET PROFIBUS Manuel d'utilisateur télécharger pdf (Page 15)

15

PROFIBUS

Network components

Optical Link Modules (OLM)

With PROFIBUS OLM (Optical Link

Modules) Version 3, optical PROFIBUS

networks can be configured in a bus,

star or hot standby ring topology.

The transfer rate of an FOC

line is not dependent on distance and

can be as much as 12 Mbit/s.

Typical OLM applications include:

· PROFIBUS-based system buses

· Inter-building networking with glass

FO cables

· Mixed networks with electrical and

optical segments

· Large expansion networks

(road tunnels, traffic control systems)

· Networks with high availability

requirements (hot standby ring

networks)

· OLM/G12-EEC for use at tempera-

tures up to –20 °C

The functions of optical link modules

include:

· Automatic recognition of all

PROFIBUS data transfer rates:

9.6 kbit/s to 12 Mbit/s including

45.45 kbit/s (PROFIBUS-PA)

· High availability by media redundan-

cy. The distance between two OLMs

in the redundant ring is limited only

by the optical sensing range of the

modules.

· Segmentable RS 485 interface

(sub D female connector)

· Unlimited multimaster mode:

Extended segmenting function for

error localization on fiber-optic cable

and RS 485 segments

· Fast localization of faults:

– Indication of module status via

floating signaling contact

– Inspection of the fiber-optic cable

quality: Measuring output for

optical receivers for logging and

validity check of FO cable line

attenuation with a voltmeter

– Indication of fault at the point of

origin, no indication of secondary

faults

· High cascading depth:

Line and hot standby ring up to

124 OLMs (only limited by monitoring

times)

· Wide range by use of glass fiber-

optic cables up to a length of 15 km

PROFIBUS bus terminals

PROFIBUS bus terminals enable a bus

node to be connected to a PROFIBUS

network.

Various versions are available:

· Up to 1.5 Mbit/s

RS 485 bus terminal

· Up to 12 Mbit/s

12M bus terminal.

Bus terminals are used:

· As a prepared unit connector for

PROFIBUS nodes

· As a simple connector of nodes to

PROFIBUS networks by clipping on

the spur line with sub D

connectors

· To implement multi-point connections

by directly butt-mounting a number of

bus terminals (up to 32 nodes per

segment) in the case of the 12M bus

terminal.

RS 485 repeater

The RS 485 IP 20 repeater connects

two PROFIBUS or MPI bus segments in

the RS 485 standard with max. 32

nodes, including a repeater.

It enables transfer rates from 9.6 kbit/s

to 12 Mbit/s (including 45.45 kbit/s for

PROFIBUS-PA).

The repeater is used:

· To increase the number of nodes

(max. 127 nodes) and the expansion

· To galvanically isolate segments

· To regenerate signals in amplitude

and time

Figure 27: PROFIBUS Optical Link Module

(OLM)

Figure 28: PROFIBUS bus terminals

Figure 29: RS 485 repeater

1 2 ... 10 11 12 13 14 15 16 17 18 19 20 ... 23 24

Commentaires sur ces manuels

Pas de commentaire