YOKOGAWA AQ1200, Руководство пользователя

Страница: 101 / 176

10-3
IM AQ1200-01EN
PON Power Meter (/PPM suffix code)
10.2 Setting PON System Optical Power Measurement Conditions and Holding the Display
3
2
1
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Index
App
Detailed Setup Screen
Press SETUP and then the OPM SETUP soft key to display the following screen.
Set the average count (1, 10, 50, 100).
Set the offset (–9.900 to 9.900 dB).
Set it for each PON system wavelength.
Set the threshold values (–80 to 40 dBm).
Set the upper and lower limits for each PON system
wavelength.
Explanation
The PON power meter is only available on models with -PPM suffix codes.
Wavelength
The wavelengths that you can specify when measuring the optical power of a PON system are listed
below. The wavelengths vary depending on the signal direction.
Signal Direction Wavelength
ONU -> OLT
1
1310 nm
OLT -> ONU 2 1490 nm and 1550 nm
1 You can measure the optical power of the upstream signal wavelength from the ONU (optical network
unit: the user’s optical terminal) to the OLT (optical line termination: the telephone exchange’s optical
terminal). The optical power of the 1310 nm (data wavelength) signal is measured.
2 You can measure the optical power of the downstream signal wavelengths from the OLT to the ONU. The
optical power of the 1490 nm (data wavelength) and 1550 nm (video wavelength) signals is measured.
Unit
You can set the optical power display unit to one of the following options.
dBm (absolute value), W (absolute value)
• The following prefixes are attached to W: m (10
–3
), μ (10
–6
), n (10
–9
), and p (10
–12
).
• The relationship between the absolute values dBm and W is indicated below.
P
dBm
= 10 × log (P
w
× 10
3
)
Where P
dBm
is the optical power in units of dBm and P
w
is the optical power in units of W.
Average Count
Averages of the measured values are displayed. You can set the number of values to average to one
of the following options.
1, 10, 50, 100
Offset
For each wavelength, the value that you specify (the offset value) is added to the measured optical
power values that are displayed.
The range is –9.900 to 9.900 dB.