The KB-0552 modules for fibre-optic connection are designed to connect fibre-optic cables with the ST type of optical connectors. The module does not contain termination of the TCL2 metallic bus (the 120 Ω resistor), so it does not have to be located at the end of the metallic line. If it is located at the end of a metallic line, the KB-0290 terminator must be used.
The optical interconnection KB-0552 modules should be connected with a duplex 62.5/125 micron or 50/125 micron fibre-optic cable (with two fibres - one for each direction of transmission) up to the distance of 1,750 m. Alternatively, two single-fibre optic cables can be used. The parameters of the KB0552 module are stated in Tab. 1.
The order number of the KB-0552 module is TXN 105 52.
Tab. 1. Basic parameters of optical connection modules of the KB-0552 bus
The type of modules |
KB‑0552 |
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The product standard |
ČSN EN 61131-2 |
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Electric item protection level in accordance with ČSN 33 0600 |
III |
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Connection |
Screw terminals |
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Duplex 2×ST |
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Power supply |
24 VDC |
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Power consumption |
1.2 W |
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The wavelength of the optical radiation |
820 nm |
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Operating temperature |
0 °C up to +55 °C |
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Surpassed attenuation |
min. 8 dB, typically 15 dB |
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Average lifetime at an ambient temperature of 55 °C (–3 dB power ) |
33 years |
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Average lifetime at an ambient temperature of 40 °C (–3 dB power ) |
68 years |
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|
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Transmitter |
|
min. |
Typical |
max. |
[dBm] |
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Transmitter optical power at 25 °C |
PT (max) |
–15,0 |
–12,0 |
–10.0 |
The total optical power |
0.355 mW |
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|
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Receiver |
|
min. |
Typical |
max. |
[dBm] |
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The input optical power "log.0" 0 up to +70 °C |
PRL(max) |
–24.0 |
|
–10.0 |
The input optical power „log.0“ at 25 °C |
PRL(max) |
–25.4 |
|
–92 |
The input optical power "log.1" |
PRH |
|
|
–40,0 |
Fibre-optic cable, parameters and requirements
Table.2: The basic parameters of fibre-optic cables with fibreglass multimode fibre
Optical connection connector |
Duplex 2× ST |
|
The wavelength of the optical radiation |
820 nm |
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The type of fibre |
multimode fibreglass 62.5/125 µm or 50/125 µm |
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Operating temperature |
–40 °C up to +85 °C |
|
Installation temperature |
0 °C up to +70 °C |
|
Typical attenuation of 1 km of cable |
|
3.5 dBm |
Maximum short-term tensile load (< 30 min.) |
500 N |
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A delay caused by the speed of propagation |
5 ns/m |
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Maximum permanent tensile load |
1 N |
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Maximum permanent bend radius |
35 mm |
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External diameter of one fibre jacket (2x) |
3 to 6 mm |
The maximum cable length depends on the power of the transmitted optical signal, receiver sensitivity, and attenuation of the cable used:
L(max) = (PT (max) – PRL(max)) / α [m]
L(max) maximum length
PT (max) minimum value of the optical power of the transmitter
PRL(max) maximum value of input optical power for log.0
α the value of cable attenuation per 1 m of length
The transmitter power also depends on the temperature.
PT (t) = PT (25°C) + ΔPT/ΔT x (t – 25°C)
The cable attenuation also depends on the temperaturte.
α(t) = α + ΔαT/ΔT x (t – 25°C)
Fig. 1. Mechanical dimensions of the ST optical connector
Fig. 2. An example of the Foxtrot system TCL2 wiring with an fibre-optic cable (see the next page).