Pinouts

Over the years, I have collected many pinouts for all sorts of interfaces, connectors, jacks, etc.  These are all stored on my laptop and in my smartphone.  It is easy enough to look these things up online, however, there are occasions when the internet is not available for whatever reason.  Thus, this is my collection of pinouts, many of which have been adapted from wikipedia articles.  Many times I put things here for my own use.  However, if I have spent ten minutes looking for the USB pin out on my smart phone, someone else has done the same thing.  Most all of these images have higher resolutions available.

Enjoy!

EIA/TIA 568a and b ethernet cable standard
EIA/TIA 568a and b ethernet cable standard

Standard networking connectors for Ethernet connections. Rumor has it that only the “A” standard is accepted for government work and the “B” standard is being depreciated.

803.3af Power over Ethernet, imposed on EIA/TIA 568 a and b
803.3af Power over Ethernet, imposed on EIA/TIA 568 a and b

Power over Ethernet pinouts. More and more commonly used in VOIP phone systems, but can also be found in wireless access points and other things of that nature.

10/100 base T cross over cable
10/100 base T cross over cable

Ethernet crossover cables are useful for connecting to similar pieces of equipment together, e.g. a computer to a computer, or a switch to a switch. Many new switches have port sensing, which will automatically cross the connection if a straight through cable is used.  Others have a specific port or a switch for a specific port which will cross over the cable.  Gigabit Ethernet uses all four pairs, thus a 1000 base T crossover looks a little bit different.

10/100/1000 base T Ethernet crossover cable
10/100/1000 base T Ethernet crossover cable

This type cable is backwards compatible with 10/100 base T systems.

Registered Jack 11/14/25
Registered Jack 11/14/25

Telephone system equipment jacks.

Registered Jack (RJ) 48, commonly used on T-1 and ISDN circuits
Registered Jack (RJ) 48, commonly used on T-1 and ISDN circuits

RJ48 and 48X used on T-1 (DS-1) and ISDN connections.  Since BRI and PRI ISDN are two wire circuits, the active pins are 4/5, which is the same as an RJ11.  I have often used RJ11 jacks for ISDN and found no issues with doing so.

T-1 (DS-1, DSX-1) crossover cable
T-1 (DS-1, DSX-1) crossover cable

Crossover cable for T-1 (DS-1 or DSX-1 interface). Note, this is different from an Ethernet crossover cable, which will not work for in a DS-1 interface.  A T-1 loopback connector goes from pin 1 to pin 4 and pin 2 to pin 5 on a 8P8C connector.

RJ21 and 21X color code.
RJ21 and 21X color code.

RJ21 and 21X connectors are often found on the side of punch blocks and make for quick connections on cabling trunks.

25 pair color code
25 pair color code

The generic 25 pair color code, which is always a good thing to have.

RS-232 data pins out for various connectors
RS-232 data pins out for various connectors

RS-232 is still commonly used for data transfer in broadcast facilities. RS-485 is also used, however, that standard is often used with screw terminals or some other generic connection.

Null modems, cables and pinouts
Null modems, cables and pinouts

Null modems for connecting equipment together and testing.

Universal Serial Buss (USB) connections and pinouts
Universal Serial Buss (USB) connections and pinouts

Various USB connectors and pinouts. USB has replaced RS-232 data ports on most newer computers.

VGA connector and pinout
VGA connector and pinout

Computer graphics card pinouts.

Computer Parallel port pinout
Computer Parallel port pinout

Computer parallel port pinout, not used very much anymore, replace by mostly USB devices. Can also be used as a limited GPI/GPO interface.  Some small automation software programs use pins 10,11,12,13 and 15 for closure information and pins 1, 14, 16, and 17 for output switching, machine starts and the like.

PS2 mouse and keyboard connector
PS2 mouse and keyboard connector

PS2 mouse and keyboard connectors, again, replaced by USB but still found on older motherboards.

RJ-45 to balanced analog and digital audio
RJ-45 to balanced analog and digital audio

RJ-45 to balanced audio. This is a fairly standardized audio application for RJ-45 connectors developed by Radio Systems/Studio Hub. It is also used by Telos/Axia and Wheatstone, although often the +/- 15 VDC power is not included.

XLR connectors, old technology, still used
XLR connectors, old technology, still used

The ubiquitous XLR connector, still used for analog audio and also AES/EBU digital audio.

8 thoughts on “Pinouts”

  1. If you have a smartphone (Well an Android), a very useful and helpful tool is “Electdroid”, which has all these pin outs and more data available at your fingertips as needed. It’s a free app, but I have found useful more than once for doing Cat 5 “on the fly”.

  2. Mike, I have and use Electrodroid often. The downside of that is that I cannot get it on my Kindle, even though the Kindle has an Android operating system. Also, others without Android devices may find the pinouts useful. I am going to do another “Apps I use” article soon.

  3. 568B is standard here in Europe, occasionally we meet legacy installations that are 568A and there we stick to the ‘house standard’ but even the commercial patch leads we buy are 568B and we don’t specify for these.

    The nice thing about standards is that we have so many to choose from..

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