M1/M2

CE4000 Cable Explorer TDR

User Manual

Axes - The horizontal and vertical axes depict the distance to the fault and the severity of the fault in dB of Return Loss. The scale of the axes is dependent on automatic or manual settings with the numeric values shown with calibrated tic mark locations.

Markers - Two markers are provided and automatically placed. The Loss and DIST measurements are made at the markers. Arrow keys can be used to move the markers.

DIST - Distance is the measurement of the cable’s distance from the TDR to the reflection from the fault.

Loss - The Loss is the measurement of the Return Loss at the fault plus two times the cable loss over the distance from the TDR to the fault.

The TDR displays the distance measurement both on the horizontal scale and digitally for the placement of the M2 marker. M1 is automatically placed at the beginning of the cable under test and M2 is placed at the point of the reflection (fault). The loss at the point of the reflection is also displayed, indicating the return loss of the reflection—or the ratio of the level of the reflection to the level of the incidence pulse in dB. The vertical scale is logarithmic, with level marks, also indicating the ratio of the reflected pulse to the incidence pulse.

Function Keys - At the bottom of the display are additional function keys, M1/M2 (F1), Pulse Width (F2), H Pos/Gain (F3) and Save (F4). These may be used to further investigate the results of the TDR display.

The M1/M2 (F1) function will sequence the Left and Right arrows between controlling the M1 marker, the M2 marker, both markers and turning off both markers. The selected marker is indicated at the top left of the display next to the screen name and is highlighted with a green background.

Use the Left and Right Arrow keys to move the selected marker. The marker may be moved one pixel at a time with one press of the button, or the button may be held down, causing the marker to sequentially move in larger increments.