1. Power up the MTTplus-420 test set. Testing should start automatically. Starting/stopping/restarting measurements from the OPM menu
) starts/stops/resets items in the OPM Summary screen - the power level graphs and the Active ONU list in
Advanced Mode
. To clear the PLOAM or OMCI list, go to the respective
menus and press the clear button.
2. Tap on
Setup
and configure the test profile settings according to the GPON class and ITU-T G.984 Test standard. Refer to GPON ITU-T
G.984 Test Standards.
Profile
Class A
Class B
Class B+
Class C
Class C+
Downstream Threshold (Marginal)
-19
-19
-25
-28
-32
Downstream Threshold (Critical)
-21
-21
-27
-30
-34
PON Span Loss (Marginal)
18
26
27
28
30
PON Span Loss (Marginal)
20
28
29
30
32
Upstream Threshold (Marginal)
-1
0
-0.5
0
1
Upstream Threshold (Critical)
-3
-2
1.5
2
3
Max Physical Length
20KM
60KM
OPM Setup menu
3. Inspect and clean the MTTplus-420 test ports. Inspect and clean the fiber patch cord from the OLT and insert it into the MTT420-plus OLT
test port.
Warning:
Never look directly into the beam of an active optical source as this may result in harmful
eye damage from radiation exposure
4. If 1490nm light is detected, the
Status
will display
OK.
Verify that the measured 1490nm signal level is green (see
). Confirm TC-Sync DS displays
OK UL/DL
. Consult VeEX technical support if you are not able to achieve TC-
Sync.
5. All DS LEDs should turn from red to Green. If any LED remains red, clean and inspect the connectors again as specified in Step 4.
6. Inspect and clean the patch cord connectors that will connect MTTplus-420 to ONU/ONT and the ONU/ONT test port.
7. Connect the MTTplus-420 to the ONU/ONT test port. If 1310nm light is detected, the Status will display
OK.
Verify that the measured
1310nm signal level is green (see
Signal and Synchronization Status
).
8. Confirm TC-Sync DS displays
OK UL/DL
. Consult VeEX technical support if you are not able to achieve TC-Sync.
9. All US LEDs should turn from red to green. If any LED remains red, clean the ONU connections again as outlined in Step 6.
Synchronizing the MTTplus-420 with the ONU Activation Process
The MTTplus-420 will synchronize to the downstream frame (from the OLT) provided the OLT is operational and 1490nm signal level is good.
The downstream frame synchronization indicator should occur almost immediately.
In order to synchronize with the ONU, the MTTplus-420 needs to see the ONU registration process. Therefore, only connect the ONU
AFTER
the MTTplus-420 application is already running. Otherwise, power cycle the ONU after the MTTplus-420 application is running if the ONU is
already connected to the MTTplus-420.
The reason for this is two-fold. First, the upstream Serial_Number_ONU PLOAM message is
only
transmitted by the ONU during its activation
and the MTTplus-420 must see this message in order to populate the ONU ID and ONU S/N fields of the OPM results page. Second, the
MTTplus-420 needs to determine its distance from the OLT and the ONU (i.e. needs to know the time difference between when a downstream
frame arrives and when the corresponding upstream frame is returned). This is determined during the ranging process.
MTTplus-420_User_Manual_RevC00
Page 36 of 75
