Step 1 : Why make a cable tester?

With the plentiful supply of cable testers on the market, why go to the trouble of making a cable tester? Because we can!!

Step 2 : Circuit Diagram


Here is the circuit diagram of the cable tester.

The cable tested is designed to test 568A and 568B data cables and USOC voice cables.

The design caters for a Master unit and a Remote. The master containers the driver and the battery (9V). The remote has 4 Red and 4 Green LEDs. This will give an indication of continuity or cross over.

Step 3 : 568A, 568B and USOC

In the world of structured cabling systems the cryptic number 568 refers to the order in which the individual wires inside a CAT 5 cable are terminated. The termination could come at either the user’s end socket, the patch panel or termination frame or even the individual leads that connect a computer to the wall socket. There are currently two different specifications with respect to the order these cables should be terminated contained in the international standards document (ISO/IEC 11801:1995).

AT&T developed the USOC standard for voice networks originally, and modified it slightly to handle data. This new data cabbling standard was 568B, and was based on the 258A original At&T specification.

More recently, higher speed networks required better cabling than that specified in ther 568B standard, the answer was the 568A standard for high speed (Cat5E and CAT 6) networks.

This tester is designed to test for continuity and reversals on USOC, 568B and 568A cables.

The termination of 568A and 568B cables differ slightly.

Step 4 : 568A Cable pinouts


Here are the pinouts and colours for 568A cables.

Step 5 : 568B Cable Pinouts


Here are the pinouts and colours for 568B cables.