Notes Regarding Suitable Pof Cables; Application With Ek1561 - Beckhoff EK15 Series Documentation

Commissioning/application notes
6.4.2

Notes regarding suitable POF cables

General information about POF cables
The standard polymer fiber is 1 mm thick and consists of a 0.98 mm thick core made of polymethyl
methacrylate (PMMA) as well as a thin sheath. In order to enable the guidance of light using the effect of
total reflection in the core, the usually very thin sheath consists of fluorinated PMMA, which has a low
refractive index. The core diameters lie between 0.06 and 1 mm, as a result of which simple plug
connections are easy to implement. Furthermore, the splicing process often used for the connection of glass
fibers and the unnecessarily high expenditure associated with it can usually be dispensed with. The
maximum operating temperature of standard POF is approximately 60 °C and has a refraction profile with
step index (SI-POF). The refractive index of the core material is around 1.49 and that of the sheath around
1.41. The difference determines the numerical aperture (NA) and thus the maximum propagation angle. With
a difference of 5% this angle is about 20 degrees in relation to the fiber axis, which leads to a reduction in
the bandwidth.
Due to the simple and almost universally applicable connection techniques compared to glass fibers, POFs
are used in particular for short transmission distances, such as inside rooms, technical equipment,
mechanical systems or cars.
POFs have an attenuation of about 140 dB/km at a wavelength of 650 Nm, so that a maximum data
transmission distance of 50 m can be achieved when used with the EK1561.
Insertion of additional connectors in the route increases the signal attenuation. For each additional
connector, the maximum permitted distances typically reduces by 6.5 m.
6.4.3

Application with EK1561

Recommended connectors and POF cables
For the connection of the EK1561 it is recommended to use the connector set ZS1090-0008 [} 62]
(Versatile Link Duplex connectors) in conjunction with a duplex polymer fiber with an outside diame-
ter of 2 x 2.2 mm (Z1190), which are available from Beckhoff.
Installation notes
• permissible bending radius (in general r ≥ 25 mm, refer to the manufacturer's data!)
• permitted tensile strength
• sensitivity of the exposed contact ends
Connecting and releasing the POF cable at the junction
To connect the cable, insert the plug (available as an accessory in the plug set ZS1090-0008) into the
connection opening until it audibly latches.
Fig. 48: Latching lug with release catch on the POF duplex plug
60 Version: 3.4 EK1122, EK15xx