LANTEK User Manual - Ideal Industries

LANTEK User Manual - Ideal Industries LANTEK User Manual - Ideal Industries

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Chapter 3 Structured Cable Field Calibration and Testing THE TDR PLOT The TDR graph is an image of the structure of the cable under test along its entire length, up to a limit of 2000 feet (609.6 meters). This graph shows anomalies by displaying blips, peaks, or valleys on an otherwise flat line. TDR Plot Layout and Controls The horizontal axis represents distance data and the vertical axis represents the percentage of reflection. Figure 3-25: TDR Graphical Plot Layout and Controls Item Table 3-6: TDR Graphical Plot Layout and Controls Function 1 Actual TDR data plot for a wire pair. When a wire graph is first displayed, the cursor is automatically positioned at the midpoint of the data. 2 Designated wire pair plotted from TDR data. (Pair A, B, C, or D) 3 Distance in meters or feet and impedance value at the cursor. 4 The vertical axis represents percentage of reflection data. 5 The horizontal axis represents distance data. 6 Left side of the display shows total length in meters or feet. Right side of the display shows the minimum/maximum level of Distance of cursor vs. total length measured in points and associated measured levels of impedance. 7 Zoom out/Zoom in keys to expand or compress the horizontal axis of the graph at the cursor. 8 Arrow keys are used to move the cursor horizontally. The screen data displayed will change to reflect the cursor position. 3-36

Chapter 3 Structured Cable Field Calibration and Testing VIEWING TDR RESULTS When the TDR diagnostic function is first started, the graphical plot is automatically scaled to the full length of the cable. A maximum of 2000 feet (609.6 meters) of cable results can be displayed on a TDR graph. When TDR is first activated, the left 10% of the graph displays prelaunch impedance signal rise distance data and the right 10% of the graph displays reflection data. ‣ Press the LEFT/RIGHT ARROW keys to move the cursor horizontally. As the cursor moves, screen data displays will change to reflect cursor position. ‣ Press the UP/DOWN ARROW keys to view TDR results from a different wire pair. The TDR test runs one time and displays the results. ‣ Press the ZOOM keys to scale the graph. At the maximum or minimum limits the key becomes inactive. ‣ TDR results can be uploaded and saved to a PC and printed. INTERPRETING TDR RESULTS Always note the cable pair currently being displayed. The shape of the reflections plotted for the pair can be used to identify and locate problems. If the cable pair has no problems along the entire length of the pair, the graph will appear as follows: ‣ The graph has an upswing point on the left most 10% of the display (start of the cable). ‣ The following 80% of the graph is relatively flat. ‣ The graph has an upswing or downswing point on the right most 10% of the graph (end of the cable). At the end of the cable (right-side), a slope to the top means the pair is open, while a slope to the bottom of the screen indicates that the pair is shorted. EVALUATING A TDR GRAPH When evaluating the TDR graph, the first consideration should be the average impedance of the cable being tested: ‣ A graph with sharp dips or spikes can identify anomalies. ‣ For subtle problems, interpretations should be based on benchmark data obtained from the analysis of many cable segments. When anomalies are detected in the cable pair, the cursor is automatically placed on the first anomaly. Press the ARROW keys to highlight the anomaly of interest. Impedance and distance values will be displayed on the screen. 3-37

Chapter 3<br />

Structured Cable Field Calibration and Testing<br />

THE TDR PLOT<br />

The TDR graph is an image of the structure of the cable under test along its entire<br />

length, up to a limit of 2000 feet (609.6 meters). This graph shows anomalies by<br />

displaying blips, peaks, or valleys on an otherwise flat line.<br />

TDR Plot Layout and Controls<br />

The horizontal axis represents distance data and the vertical axis represents the<br />

percentage of reflection.<br />

Figure 3-25: TDR Graphical Plot Layout and Controls<br />

Item<br />

Table 3-6: TDR Graphical Plot Layout and Controls<br />

Function<br />

1 Actual TDR data plot for a wire pair. When a wire graph is first displayed, the<br />

cursor is automatically positioned at the midpoint of the data.<br />

2 Designated wire pair plotted from TDR data. (Pair A, B, C, or D)<br />

3 Distance in meters or feet and impedance value at the cursor.<br />

4 The vertical axis represents percentage of reflection data.<br />

5 The horizontal axis represents distance data.<br />

6 Left side of the display shows total length in meters or feet.<br />

Right side of the display shows the minimum/maximum level of Distance of<br />

cursor vs. total length measured in points and associated measured levels of<br />

impedance.<br />

7 Zoom out/Zoom in keys to expand or compress the horizontal axis of the graph<br />

at the cursor.<br />

8 Arrow keys are used to move the cursor horizontally. The screen data displayed<br />

will change to reflect the cursor position.<br />

3-36

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