SNLA334 june   2023 DP83867CR , DP83867CS , DP83867E , DP83867IR , DP83867IS , DP83869HM

 

  1.   1
  2.   DP83867 and DP83869 TDR
  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. 2DP83867 and DP83869 TDR Implementation
    1. 2.1 TDR Configuration
    2. 2.2 TDR Algorithm
      1. 2.2.1 TDR Algorithm Example Flow
      2. 2.2.2 TDR Algorithm Matlab Example
  6. 3Summary
  7. 4References

2.2.1 TDR Algorithm Example Flow

Table 2-6 shows the TDR results from a 100m CAT5e cable.

Table 2-6 TDR Data Table Example
peak_index (0x180) peak_value (0x185) peak_sign (0x18A)
F 2D 0
93 11 0
0 0 0
0 0 0
0 0 0

The algorithm starts by checking to see if the last 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.

GUID-20230525-SS0I-ZRHH-CW7Z-2SGZ22ZLCPNC-low.svg Figure 2-2 TDR Algorithm Example Flowchart