Siemens SIMATIC NET PROFIBUS Instrukcje Operacyjne Pobierz pdf (Strona 37)

Installation and Maintenance

5.1 Installation

SIMATIC NET PROFIBUS Optical Link Module OLM V4.0

Operating Instructions, 01/2013, C79000-G8976-C270-03

Shield connections

Figure 5-2 Securing shielded cables with cable

clamps and cable retainers

(schematic image)

Please note the following points when connecting

the cable shield:

 Connect the shield braid with cable clamps

made of metal.

 The clamps must surround the shield

making good contact over a large area

(see Figure 5-2).

 Only contact the SIMATIC NET

PROFIBUS cables via the copper braid

shield and not via the aluminum foil shield.

The foil shield is applied to one side of a

plastic foil to increase the tensile strength

and therefore is not conductive!

 The shielding of all cables entering a

switching cubicle from outside must make

large area contact with chassis ground.

 The braid shield of the cables must not be

damaged when stripping the cable jacket.

Tin-plated or galvanically stabilized

surfaces are ideal for good contact

between grounding elements. With tin-

plated surfaces, the necessary contact

must be established using screws. Painted

or varnished surfaces at the contact points

are unsuitable.

 Shield clamps or contacts must not be

used as strain relief. The contact to the

shielding rail could deteriorate or be

broken altogether.

Optical link power budget, aging and environmental requirements

When using OLM V4.0 devices, make sure that they are not exposed to high temperatures

for no good reason. The aging of the devices increases radically in high temperatures. The

same applies to the connected fiber-optic cables. They age faster under the influence of

temperature and high humidity. The deterioration caused by humidity especially applies to

plastic fiber-optic cables.

The described deterioration of devices and fiber-optic cables is offset by the link power

margin. This is obtained from the difference between the receiver sensitivity and the

minimum input optical power (see section

4.1) along with the cable attenuation that derives

from the max

imum operating distance.

1 2 ... 32 33 34 35 36 37 38 39 40 41 42 ... 63 64

Komentarze do niniejszej Instrukcji

Brak uwag

Siemens SIMATIC NET PROFIBUS Instrukcje Operacyjne Strona 37

Komentarze do niniejszej Instrukcji

Powiązane produkty i podręczniki dla Networking Siemens SIMATIC NET PROFIBUS