Fracarro 270662, Operating Instructions Manual, Page: 9 / 16

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3.2 Power supply
OPT-RX QUAD MICRO: The optical receiver can be powered by STB (set-top-box) or with an external power supply to DC IN optional
input.
OPT-RX 4 MICRO: the power supply is provided via SAT outputs.
3.3 Fibre optic connection
ATTENTION: Direct connections are not allowed between the OPT-TX DT and OPT-RX QUAD MICRO/ OPT-RX DT
4 MICRO unless the correct line optical attenuators are used, because the maximum input power into the receivers can not
exceed -8dBm.
An optical power meter must be used to check the optical input power to the receivers .
Use the SC-APC -> MINI links (PR ADAPT, code 287226) to connect the OPT devices to the optical distribution (VOV and VOT
devices).
Attention: To conserve and protect the contact surfaces of the optical connectors the protective caps must be
left in position until when the connections are made or can be cleaned using the correct tools.
4. USER’S INSTRUCTIONS
4.1 Dimensioning a Fibre Optic system
The optical attenuation range allowed is 15 to 21 optical dB. Refer to the product specifications to calculate the optical attenuations
for the devices.
The receivers can guarantee that the correct level of TV and SAT signals are available to the end users sockets. This guarantee
is on the provision that the input level of the optical signal is between -8dBm and -14dBm and the RF signal incoming to
the OPT-TX DT complies with the specifications of its manual.
ATTENTION:
• Direct connections are not allowed between the OPT-TX DT and Receivers , unless the correct line optical
attenuators are used.
• An optical power meter must be used to check the optical input power to the receivers and to prevent damaging the receiving
photodiode (damage can be caused if the optical input signal is higher than 0dBm).
The output level to the OPT-RX optical receivers depends on the number of signals transmitted through the fibre and the optical
attenuation of the section.
Remember that 1dB of optical fall equals 2dB of attenuation to the electric level (RF).
Below some reference levels are given for the output signals to the receivers.
OPT-RX QUAD MICRO
Shown below are some of the reference levels of the signals output to the receiver OPT-RX QUAD MICRO
Table 1: Indications of output levels to the OPT-RX QUAD MICRO.
Note: 1dB optical equals 2dB at electric level (RF).
RF output level for MUX TV RF output level for TP SAT
No. for MUX Optical input power
-14 to -8 dBm
Numero TP Optical input power
-14 to -8 dBm
40 60 to 72 40 62 to 74
16 64 to 76 16 66 to 78
8 67 to 79 8 69 to 81
4 70 to 82 4 72 to 84
4.2 Output levels to the optical receiver