Siemens SIMATIC NET PROFIBUS Owner's Manual page 293

SIMATIC NET PROFIBUS Plastic Fiber Optic
General Instructions for Working with
SIMATIC NET PROFIBUS Plastic Fiber Optic Cables
Please note the following instructions to avoid damage to cables:
F
Make sure that the selected cable is suitable for the area of application.
You should, for example, check the following:
– Required temperature range
– Resistance of the jacket materials to chemicals, water, oils, rodents etc.
to which the cable may be exposed in your application
– Required mechanical properties (bending radii, tensile strength, transverse compressive
strength)
– Required behavior of the cable in fire
– Suitability of the cable including the connectors for the devices to be interconnected
If necessary, use a special cable that meets your requirements. Your SIMATIC NET contact in your
local Siemens branch will be happy to advise you.
F
Never exceed the maximum permitted loads (tensile load, transverse compressive load etc.)
specified in the data sheet of the cable you are using. Excessive transverse compressive load can,
for example, result from using screw clamps to secure the cable.
F
Only use plastic fiber-optic cables with devices approved for this plastic FO cable. Keep to the
maximum permitted cable lengths.
F
When cutting cables to length, make sure that no loops are formed and that the cable is not twisted.
Loops and torsion under tensile load can cause kinks or cracks that may mean irreparable damage to
the cable.
F
Follow the instructions in this manual and use the tools described here.
F
Set the cutting depth of the cable knife (part of the stripping tool set, order no. 6GK1 905-6PA10) to a
depth of 1.5 mm prior to use.
The cutting depth is set with the adjusting screw at the end of the handle:
- Turning the adjusting screw clockwise increases the cutting depth
- Turning the adjusting screw counter clockwise reduces the cutting depth
F
Make sure that the outer jacket and buffers of the cable and the plastic fibers are not damaged.
When stripping the buffer from the fiber, use only the opening in the stripper marked AWG 16.
Nicks or scratches can allow light to escape and can therefore lead to increased attenuation values
and failure of the transmission path. With time, such defects can also lead to breaks in the fiber and
to failure of the network.
F
When grinding and polishing make sure that there is only slight pressure from the connector on to the
foil to avoid fusion of the connector and fiber plastic.
F
Make sure that you keep to the bending radii when grinding and polishing particularly when the
cables are supported to provide mechanical strain relief. In this case, make sure that you strip an
adequate length of the outer jacket.
F
The polishing holder has four recesses on the bottom surface. Replace the polishing holder as soon
as any of these recesses is no longer visible.
F
Never insert contaminated connectors or connectors with fibers extending beyond the end face into
the device sockets. The optical transmitter and receiver elements could otherwise be destroyed.
F
When assembling plug adapters and when fitting the cable to them make sure that the transmit and
receive lines are crossed over.
Installation Instructions for Simplex Connectors
Page 3