I recently bought some RS485 cable, it had two pairs, both had stripes. One was mostly blue with a white stripe and the other was white with a blue stripe.

enter image description here

I'm mostly used to ethernet with a pair consisting of completely solid and white with a stripe.

Large phone cables have solid with white stripes, and solid.

So is there a meaning to any of these? Is the striping set by manufacturers or have any meaning beyond indicating a pair?


User @Justme was correct about it being a twisted pair but the stripped line indicates positive and solid colored line indicates negative.

So for an example, let's say you have two twisted pairs: One for RX and TX. Much like RJ45, etc., RS485 will also have RX and TX signals.

enter image description here Picture can be found here... Not my picture. The positive and negative wires are for differential signaling.

You can find more details on that with this Network Engineering StackExchange answer (What do the positive and negative (+/-) transmit and receive pins mean on Ethernet cables?).

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  • \$\begingroup\$ Just note that RS-485 has no standardized wiring convention. \$\endgroup\$ – Caleb Reister Sep 19 '19 at 20:09
  • \$\begingroup\$ Also, take a look at the Wikipedia article on TIA/EIA-568. \$\endgroup\$ – Caleb Reister Sep 19 '19 at 20:10
  • \$\begingroup\$ @CalebReister Thank you for the additional reading material. However, the link to my picture already provides this information. \$\endgroup\$ – user103380 Sep 19 '19 at 23:05

It is just to show which wires are twisted as a pair, no electrical meaning.

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  • \$\begingroup\$ This does not really answer the question, and you provide no sources, although it is true that RS-485 does not specify a connector or pinout. \$\endgroup\$ – Caleb Reister Sep 19 '19 at 18:51
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    \$\begingroup\$ @CalebReister This answer indicates no sign of plagiarism since there doesn't appear to contain any fundamental theory. Had the answer contain something like, "This is a twisted pair that reduces the amount of electrical noise in the wire blah blah blah. These statistical numbers indicate blah blah blah...", without citing anything, then it would be plagerism. Also, this is indeed answer even though it is short. It answers the question, does it not? You also need to do some research on what RS485 is. RS485 is not a connector, it's a standard. You're thinking of DB9 and DB25. \$\endgroup\$ – user103380 Sep 19 '19 at 19:14
  • \$\begingroup\$ It is important to be able to identify which conductor is which in a twisted pair cable. -1 for saying that it doesn't matter. \$\endgroup\$ – Dwayne Reid Sep 19 '19 at 19:48
  • \$\begingroup\$ Of course it is important to determine which conductor is which in a pair. Correct me if I am wrong, but the question was about stripes - it really does not matter if it is stripey blue and stripey white or solid blue and solid white, stripyness does not have an electrical meaning, beyond indicating the pair. In a cable with huge amount of pairs, the stripes may have other colors than white, to separate a blue pair with white stripe from say blue pair with yellow stripe, or whatever the coding happens to be. \$\endgroup\$ – Justme Sep 19 '19 at 20:18
  • \$\begingroup\$ I think the ambiguity of saying "has no electrical meaning" is probably the reason Dwayne downvoted. You're right about wire convention, though. \$\endgroup\$ – user103380 Sep 20 '19 at 1:04

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