SNLA428 june   2023 DP83826E

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Time Domain Reflectometry
    1. 1.1 Example Connections
      1. 1.1.1 Open Circuit Cable
      2. 1.1.2 Short Circuit Cable
  5. 2TDR Implementation
    1. 2.1 DP83826 TDR Configuration
    2. 2.2 TDR Algorithm
      1. 2.2.1 TDR Algorithm Example Flow
      2. 2.2.2 TDR Algorithm Matlab Example Code
  6. 3Summary
  7. 4References

TDR Algorithm Example Flow

Table 2-5 shows the TDR results from a 100 m CAT7 cable.

Table 2-5 TDR Data Table Example
Segment peak_index (0x180) peak_value (0x185) peak_sign (0x18A)
2 0 0 0
3 0 0 0
4 0 0 0
5 78 11 0
1B C 6 800
1A 6 44 0

The algorithm starts by checking to see if the first element the array peak_val is greater than the current threshold, 10. If it is not greater than 10, it moves onto the next row. If it is greater, the algorithm will look for the corresponding row in the array peak_indx and use that value to calculate the location of the fault. Then, the algorithm will look at the corresponding row of peak_sign to determine the fault type. A 0 means the fault is open, a nonzero value means that the fault is a short.

Figure 2-2 DP83826 TDR Example Flowchart
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