How do i interpret the pin-out diagrams?

Started by kr0n, Nov 21, 2006, 17:31

Previous topic - Next topic


Hi all,

Wonder if i could get some help deciphering the pin-out diagrams in the website.  I need to make up one of the cisco cables shown on the website (DB60 --> DB37 DTE) (

I am not new to pin-out diagrams however, i am a little confused by the format used on the website.  Basically, its quite obvious where say pin A goes to pin B but how do i interpret the following pin conventions used :

Shorting group - dose this mean the pins are shorted, i.e. two pins on the same connector are shorted together?  For example, pin J1-1 and pin J1-6 ?

Single - I take it this is for a single connection from pin A on one connector to pin B on another, e.g. J1-15 --> J2-16

Twisted pair - This would usually indicate that pins A and B on one connector go to pins B and A on another connector (respectively), so that connections to A and B are crossed, is that right?  what i mean is that if pin J1-5 goes to J2-6 then J2-5 would go to J1-6.  Looking at the pinouts, there are a lot of pins labelled 'twisted pair' but the pins do not match up?  Does that matter, or do i just do as it says and connect them as shown?

Any help appreciated,


lways know what you say, but don't always say what you know!


As I understand it, the pins indicated in a single "shorting group" are shorted together with the connector. It seems in the wiring diagram that MODE_1 and MODE_DCE are input signals that are active low and therefore pulled down to the ground to tell the device at that end to function in a certain way.

The word "single" indicate a single-wire connection. Grounding needs only a single wire and using a twisted pair is outright stupid.

"Twisted pair" indicates that the balanced signals are wired with two wires that are twisted around each other. This is a simple noise reduction technique that reduces cross-talk with the other wires. Please note that you have two different connectors described in the wiring diagram. Therefore their pinout will be different at the connectors.

Just pull your browser window as wide as it's needed (and as possible) so that the table cells word-wrap as little as possible. Then you can use a ruler to simplify reading which pin is connected to where and remember to keep the twisted pairs as indicated in the wiring diagram. Otherwise you'll possible end up with a poorly working cable.