Ethernet Connectors (For Info Only)

Thanks for the report-back. I'm not surprised DB9 works. It might have more untwist than RJ, but it has fewer right-angles. There are wierd self-inductive effects in conductors with sharp right angles. Good PCB traces have 2 45deg turns.

-- Robert

ARRGGHHH!!!! It's not DB9. It's DE9!!! Check the connector manufacturer catalogs.

Strictly correct. However, DB9 is common usage. _Very_ common: Google gives only 688 hits for DE9 connector while 530,000 for DB9 connector.

-- Robert

A similar situation occurs with "RJ45", which strictly speaking is a keyed 8p8c modular connector wired for a analog leased line modem, sharing no wiring in common with 10/100 ethernet.

Not only is the designation incorrect for ethernet, but the specified connector and wiring pattern for RJ45 are incompatable with ethernet.

I thought Registered Jack 45 was correct for both, but the wiring itself was different. i.e. the "housing" of RJ45 is common to both, but wiring is different.

The Amp site gets numerous hits on "RJ45" but none at all on "8p8c". OTOH, Froogle gets about 2500 hits on "8p8c" most of them plugs or jacks, vs about 15,000 for "RJ45 plug", most of them either on cables or consumer packaged.

(snip)

That is what is different between RJ series and the DB (DA ... DE) series. The RJ series specifies not only the plug and jack, but the wiring, too.

RJ11, RJ12, and RJ13 all use the same six contact plug/jack but with different wiring.

-- glen

Then there is RJ48.

Don't forget RJ14 and RJ25.

RJ12 and RJ13 are very similar, but are incompatible with RJ14 or RJ25, can anybody guess why?

What is the difference between RJ12 and RJ13?

What happens when you plug a phone wired for RJ12/RJ13 into a jack wired for RJ14 or RJ25?

What RJ arrangements do not use a modular connector?

The concept behind the Registered jack is the Universal Service Ordering Code (or USOC), which is used by the telephone companies to define specific services, such as custom calling features, billing arangements, or physical connections. The idea being that you can order services from any telco in the country, using the USOC, and receive the same service no matter who the telco is, or where in the country you are located.

There's a whole variety of RJxx designations, using about 5 different connectors, in a variety of wiring patterns.

Connector types that I can think of offhand are: