recently I found a cable in my drawer which one side has a RJ45 connector with an unknown color code of red brown black white green I tried to solve it by myself but I couldn't so I upload a picture if you can tell me what it is used for. ThanksUSB and RJ45

2 Answers 2


That's no network cable.

Likely, it's a console cable, connecting a 10P10C(!) console port on a device to a USB port on a PC. It might be from a UPS (usually has a key next to pin 1) but unless you can verify the pinout I wouldn't connect it anywhere.


The wiring exactly match the one given on this page so it is most probably an APC UPS serial cable

APC part# 940-0127B, 940-127C and 940-0127E
APC Pin  USB Pin    Description
1           1       USB +5V (red wire)
4           shield  chassis ground
7           4       USB GND (black wire)
9           2       USB Data- (white wire)
10          3       USB Data+ (green wire)

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