To test the DC Resistance of a CATx cable:
Easily done via the MS-TestPro From the Tools page, in the DCR DC Resistance button.
The DC Resistance can test:
- Loop Resistance
- Parallel DC Resistance Unbalanced
- Pair to Pair Resistance Unbalanced
Loop Resistance – represents the DC loop resistance (in ohms) of a cable, and is calculated as the sum of the DC resistance of the two conductors in a pair.
Resistance of under 20 ohms indicates that the pair should be capable of delivering the minimum of 80% of the power to the remote side.
Parallel DC Resistance Unbalanced displays the parallel resistance of the CATx two conductors in each cable pair. For each pair, the difference is expressed in ohms, as shown in the figure below
Pair-to-Pair Resistance Unbalanced displays the difference in DC resistance between the four pairs in the cable. For each pair, the difference is expressed in ohms, as shown in the figure below.
A difference of under 0.2 ohms or 5% (the higher between the two) indicates that the pair should be capable of delivering the required common-mode current needed to effectively support PoH (PoE) and data transmission over the pair.
You can export your results in CSV format report, and also Save them locally.