IEC 62150-2:2010 pdf – Fibre optic active components and devices-Test and measurement procedures – Part 2:ATM-PON transceivers.
7.1.4 Measuring procedures
The measuring procedures shall be carried out as follows:
a) Drive the tested ATM-PON transceiver under normal operating conditions and confirm that the alarm output voltage is in the low-level (VALL) range specified in lEG 62149-5.
b) The tested ATM-PON transceiver and a reference Tx shall be installed in the configuration shown in Figure 1.
C) Apply the 15552 Mbit/s-NRZ-PRBS 223_i signal (mark ratio 50 %) to the signal input terminal.
d) Adjust the variable optical attenuator so that B is much lower than TH and record the B value as a
e) Adjust the variable optical attenuator so that P8 exceeds TH and record the alarm output voltage.
f) Confirm that the alarm output voltage is changed from low-level (VALL) to high-level (ALH) specified in IEC 62149-5 when P8 is around TH•
g) Adjust the variable optical attenuator so that B reaches the overload value (S0) and record the alarm output voltage and confirm that the alarm output voltage is in the high- level (VALH) range specified in IEC 62149-5.
h) Adjust the variable optical attenuator so that P8 reaches IL with recording the alarm output voltage.
i) Confirm that the alarm output voltage is changed from high-level (ALH) to low-level (FALL) when B is below 111L
As a result of the above procedures. a relation between P8 and the alarm output voltage is obtained as a hysteresis curve as shown in Figure 2. This hysteresis curve is the measurement data of receiver alarm function.
a) Design a burst signal pattern defined by frame length A, burst signal length B, and the number of the burst signals within a frame n as shown in Figure 5. 8 is 56 bytes for ATMPON transceivers.
b) Operate the tested ATM-PON transceiver under normal operating conditions and apply the designed burst signal pattern to the signal input terminal from the pulse pattern generator. The burst signal itself or its envelope signal should be used as a trigger for the oscilloscope to reduce the timing jitter.
c) Display the optical signal waveform, which will have been converted into the electrical waveform by the OlE converter, on the display of the oscilloscope.
d) According to IEC 61280-2-2, calculate the extinction ratio and perform the mask test using the masks defined in ITU-T G.983.1.
e) Repeat the above calculation and mask test for each burst signal within a frame.
7.54 Testing procedures
The testing procedures shall be carried out as follows:
a) Operate the tested ATM-PON transceiver under normal operating conditions and apply the 155,52 Mbit/s-NRZ-PRBS 223_i signal to the signal input terminal. This PRBS signal corresponds to a A = ii x 8” case of a burst signal.
b) The clock signal from the pulse pattern generator is used as a trigger for the oscilloscope.
C) Display the optical signal waveform, which will have been converted into the electrical waveform by the OlE converter, on a display of an oscilloscope.
d) According to lEG 61280-2-2, calculate the extinction ratio and perform the mask test using the masks defined in ITU-T G.983.1.
e) Confirm that the mask test has passed or tailed and that the calculated extinction ratio is within its specified range (from 5,8 dB to 10 dB).
7.6 Receiver sensitivity (S) and receiver overload (S0)
7.6.1 Purpose
This subclause defines the testing and measuring procedures for the receiver sensitivity
(S: —30 dBm for class B modules, —33 dBm for class C modules) and receiver overload
(S0:—8 dBm for class B modules, —11 dBm for class C modules) of the ATM-PON transceiver.
7.6.2 Testing and measuring configuration
Unless otherwise specified, the tested transceiver shall be installed in the measuring and testing configuration as shown in Figure 8. Optical splitters whose calibration factors have been estimated by the procedures described in 7.1.3 shall be installed in this configuration. If more than 40-dB-attenuation can be obtained by the variable attenuator-i and -2 in Figure 8. alternative procedures denoted by ‘ can be taken.