OTDR Trace Features - DTX Compact OTDR Module

Reading a Typical OTDR Trace from the DTX Compact OTDR Module

1. Reflective event caused by the OTDR port connection.
2. Reflective event caused by the first connection in the cabling. This trace was produced using launch fiber compensation, so the end of the launch fiber is marked with a dotted line and is the 0 m point for length measurements.
3. Small event caused by a sharp bend in the fiber.
4. Reflective event caused by the last connection in the cabling. The dotted line marks the end of the fiber under test and the beginning of the receive fiber.
5. Reflective event caused by the end of the receive fiber.
6. Overall loss of the cabling. Since launch and receive fiber compensation was used, the overall loss excludes the loss of the launch and receive fibers.

Using the Measurement Cursor
You can use the cursor on the OTDR trace to measure distances and losses along the cabling. To make measurements with the cursor:

1. Press F2 Change to Cursor if necessary to set the arrow keys to cursor mode.
2. Move the cursor to a starting point for a measurement. Use RIGHT ARROW, LEFT ARROW to move the cursor left or right or UP ARROW, DOWN ARROW to move the cursor to the previous or next event.
3. Press ENTER to mark the starting point for the measurement.
4. Use RIGHT ARROW, LEFT ARROW, UP ARROW, and DOWN ARROW to move the cursor to the ending point for the measurement.
   The following readouts appear on the screen:
• Δ m or Δ ft: The distance between the cursor and the mark.
• Δ dB: The difference in the power levels (in decibels) between the cursor and the mark.

5. To clear the mark press ENTER.

Zooming the Trace
The zoom function lets you magnify the trace horizontally or vertically. To zoom the trace:

1. Press F2 Change to Cursor if necessary to set the arrow keys to cursor mode.
2. Use RIGHT ARROW, LEFT ARROW to place the cursor near the feature you want to magnify.
3. Press F2 Change to Zoom to set the arrow keys to zoom mode.
4. Use RIGHT ARROW, LEFT ARROW, UP ARROW, DOWN ARROW to zoom the trace vertically and horizontally.

The Event Table
To see a list of the events along the cabling, press F1 View Events from the OTDR Results screen or the OTDR Trace screen.