Creating custom limits for OTDR tests - DTX Compact OTDR Module

You can create up to nine custom fiber limits for OTDR tests. Each limit can include multiple fiber types. Listed below are the settings used in custom OTDR limits.

To create a custom fiber limit for OTDR tests:
  1. Turn the rotary switch to SETUP; then select Fiber OTDR.
  2. Select Test Limit; then select Custom. If Custom is not in the list, press F1 More to see more test limits.
  3. Press F1 Create to create a new limit.
  4. On the Custom Limit screen, select Name; then use the text editing screen to enter a name for your custom OTDR limit. Press SAVE when you are done.
  5. On the Custom Limit screen, select Use Default Values From, select a limit group; then select a fiber limit as a baseline for your custom limit.
  6. On the Custom Limit screen, press F1 Select Fiber; then do one of the following:
    • Highlight a fiber type for the custom limit.
    • To add a fiber to the list, press F2 Add Fiber, select a fiber group, select a fiber type; then highlight the added fiber on the Custom screen.
  7. With the desired fiber type highlighted on the Custom Limit screen, press F1 Edit Limit.
  8. The Custom Limit screen shows other settings on multiple tabs for the OTDR test limit. Use the UP ARROW or DOWN ARROW and ENTER to select settings to change. Use the LEFT ARROW or RIGHT ARROW to move among the tabs.
  9. From the Custom Limit screen, press N when you are done creating the limit. The tester saves the custom limit in the Custom list, with asterisks (*) before and after the name.


Settings for Custom OTDR Limits Setting Description

  • Length: Enter a maximum length for the cabling.
  • Reflective Event Loss: Enter a maximum value for connector loss. A typical value is 0.75 dB.
  • Non-reflective Event Loss: Enter a maximum value for splice loss. A typical value is 0.3 dB.
  • Event Reflectance: Enter a maximum reflection value for a single event. A typical value is -35 dB.
  • Overall Loss: Enter a maximum value for the loss of all components and fiber in the cabling at each wavelength tested.
  • Overall Attenuation Coefficient: Enter a maximum value of attenuation per kilometer for the entire length of the cabling at each wavelength tested.
  • Segment Attenuation Coefficient: Enter a maximum value of attenuation per kilometer for a fiber segment in the cabling at each wavelength tested.

Note
The segment attenuation coefficient for shorter segments (50 m to 500 m, depending on wavelength and fiber characteristics) may not be measurable.


Editing Custom Settings

The editing function lets you change values in existing custom settings. To edit an existing custom cable, fiber type, test limit, or outlet configuration:

  1. Turn the rotary switch to SETUP; then select Twisted Pair, Fiber Loss, or Fiber OTDR.
  2. On the Twisted Pair, Fiber Loss, or Fiber OTDR menu, select the item that includes the custom settings you want to edit (Cable Type, Fiber Type, Test Limit, or Outlet Configuration).
  3. If you selected Test Limit, press F1 More.
  4. Select Custom.
  5. Use the UP ARROW or DOWN ARROW to highlight a custom setting; then press F3 Edit.
  6. Make your changes on the Custom screen; then press SAVE.


Deleting Custom Settings

To delete a custom cable, fiber type, test limit, or outlet configuration:

  1. Turn the rotary switch to SETUP; then select Twisted Pair, Fiber Loss, or Fiber OTDR.
  2. On the Twisted Pair, Fiber Loss, or Fiber OTDR menu, select the item that includes the custom settings you want to delete (Cable Type, Fiber Type, Test Limit, or Outlet Configuration).
  3. If you selected Test Limit, press F1 More.
  4. Select Custom.
  5. Use the UP ARROW or DOWN ARROW to highlight a custom setting.
  6. Press F2 Delete; then press F3 Yes.