RS-485 Pinout to RJ45

Is there a standard (or at least, recommended) pinout for an RS-485 network to an 8-pin RJ45 style jack?

I Googled it and it seems to very wildly by manufacturer and/or product.

I have to layout a board for a product that will sit on an RS-485 half-duplex network with up to 15 nodes.

Appreciate the help!

Reply to
mpm
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There are no standard. Just select one of the four pairs.

When looking for various notation for devices from different manufacturers, they may interpret the polarity differently. If one manufacturer uses D+/D- notation, an other manufacturer will have the opposite polarity. Only the official standard A/B notation seems to be OK with all manufacturers, so use it in your documentation (not D+/D-).

You may (or may not) need a signal ground, so you may have to use an other pair for this.

Reply to
upsidedown

I'd at least use the Ethernet pairing, so you can use standard cables.

Reply to
jlarkin

Preferably (because some old cables from pre-gigabit may still be useful) use positions 1,2 or positions 3,6 (the orange/orange-white or the green/green-white pairs).

Reply to
whit3rd

ptechnology.com:

ork to an 8-pin RJ45 style jack?

uplex network with up to 15 nodes.

also reduces the risk of frying it is plugged into a POE ethernet

Reply to
Lasse Langwadt Christensen

Cisco console lead?

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Adrian C
Reply to
Adrian Caspersz

oh, ignore that. Differential ....

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Adrian C
Reply to
Adrian Caspersz

Lasse Langwadt Christensen wrote in news:eb63850e- snipped-for-privacy@googlegroups.com:

They are pretty smart and would likely not energize the port.

Every POE I saw was a managed port that was energized only through software, but once energized, I suppose one could plug a cable into a "turned on" port. But I think they have load sensing too, and would shut the P part off. Likely shut it of for failing to handshake ENET too.

If you are making your own link, you could use a ten pin wide connector. That would keep anyone from inserting it into an ENET port. That would be RJ-50. Crimpers or the die might be more difficult to find.

Reply to
DecadentLinuxUserNumeroUno

No, it would not. 8P8C is the same width as 10P10C.

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  When I tried casting out nines I made a hash of it.
Reply to
Jasen Betts

mandag den 19. august 2019 kl. 06.04.37 UTC+2 skrev snipped-for-privacy@decadence.org:

it depends, the so called "passive POE" is just a powersupply with + connected to one pair and - to another pair

Reply to
Lasse Langwadt Christensen

They also often put power on the 1-2 and 3-6 pairs.

Reply to
Tom Del Rosso

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