GPON/XGS-PON Test Procedure

The FX120/FX120 Lite is designed for use at the customer premises to aid with ONT/ONU activation and troubleshooting.

 

The FX120 is connected at the customer premises.

 

  1. Power on the FX120/FX120 Lite test set. Testing should start automatically. Restarting measurements from the OPM menu (see OLT Information Table) resets items in the OPM Summary screen - the power level graphs and the Active ONU list in Advanced Mode. To clear the PLOAM list, go to the respective PLOAM menu and press the clear button.

  2. Tap on Setup and configure the test profile settings according to the xPON class and ITU-T Test standards.

    3. GPON OPM Setup menu

     

    XGS-PON OPM Setup menu

  3. Inspect and clean the FX120/FX120 Lite test ports. Inspect and clean the fiber patch cord from the OLT and insert it into the FX120/FX120 Lite OLT test port.

    4. 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 1490/1577nm light is detected, the 1490/1577nm Status will display OK. Verify that the measured 1490/1577nm signal level is green (see OPM Test Mode).

  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 (see GPON/EPON LED Status Indicators).

  6. Inspect and clean the patch cord connectors that will connect FX120/FX120 Lite to ONU/ONT and the ONU/ONT test port.

  7. Connect the FX120/FX120 Lite to the ONU/ONT test port. If 1310/1270nm light is detected, the Status will display OK. Verify that the measured 1310/1270nm signal level is green (see OPM Test Mode).

  8. All US LEDs should turn from red to green. If any LED remains red, clean the ONU connections again as outlined in Step 6.

  9. Confirm TC-Sync status displays OK DL. If you are not able to achieve TC-Sync, contact VeEX Inc. Support.

GPON and XGS-PON Threshold Standards

 

For latest revisions of GPON standards, please visit https://www.itu.int/rec/T-REC-G.984.2-201908-I and for XGS-PON standards, please visit https://www.itu.int/rec/T-REC-G.9807.1/en.

 

Synchronizing the FX120/FX120 Lite with the ONU Activation Process

The FX120/FX120 Lite will synchronize to the downstream frame (from the OLT) provided the OLT is operational and 1490/1577nm signal level is good. The downstream frame synchronization indicator should occur almost immediately.

In order to synchronize with the ONU, the FX120/FX120 Lite needs to see the ONU registration process. Therefore, only connect the ONU AFTER the FX120/FX120 Lite application is already running. Otherwise, unplug and replug the ONU the ONU after the FX120/FX120 Lite application is running if the ONU is already connected to the FX120/FX120 Lite.

If the OLT and an active ONU are connected to the FX120/FX120 Lite before starting the test application, the FX120/FX120 Lite will not see the ONU activation and the above process will not be completed. In this instance, LOF will be reported for the upstream side; no ONU ID or ONU S/N information on the OPM results page will be displayed.