RE: Electronics question

["Paul Gordon" <paul_gordon@xxxxxxxxxxx>]

Yes, Until recently I too thought all RJ45 connections were 8-pin
only.
Having got this device, I have discovered that there is actually a 10-pin
version of the RJ45 plug... - AFAICT it is an "official" RJ45
spec, but
almost nothing ever uses it... - except this Avocent box of course, which
has the CTS & RTS lines on pins 1 & 10, - which obviously aren't
available
on any of the connectors I've got. - So it's fortunate that so far, nothing
I've needed to run through this device needs or cares about hardware flow
control. (I don't think very much hardware does these days). Pins 2-9 on
the
10-pin spec correspond to pins 1-8 on the 8-pin spec.

If you look down the inside of an 8-pin RJ45-DBxx modular adapter, you
might
even be able to see the marks in the plastic where the moulds are obviously
able to make either 10-pin or 8-pin devices. - You can on the ones I've got
here...

Paul G.


-----Original Message-----
From: ukha_d@xxxxxxx [mailto:ukha_d@xxxxxxx] On Behalf Of
Dave McLaughlin
Sent: 26 June 2009 13:20
To: ukha_d@xxxxxxx
Subject: RE: [ukha_d] Electronics question

Hi Paul,



Because the connector on the Avocent device is not connected on that pin.
You only have power to the connector that goes to the device you need to
power up.



Eg. (exact pin No.s may be wrong but it should make sense)



Avocet                  Other device

D type                   D type



2------------------2             RXD

5------------------5             GND

4              +12V from power supply.



PS.. How do you get 9 pins on an RJ45 connector. I thought it only had 8?



Dave.

From: ukha_d@xxxxxxx [mailto:ukha_d@xxxxxxx] On Behalf Of
Paul Gordon
Sent: 26 June 2009 13:32
To: ukha_d@xxxxxxx
Subject: RE: [ukha_d] Electronics question








That's not a bad idea... - nut how do you guarantee isolation between the
+12V you put on the DTR pin going back to the port on the Avocent device?

I've got another potential route to investigate as well now... - the user
manual for the device clearly and unequivocally shows the DTR line to be in
pin 9 of the RJ45 socket, and so that's what I've been using. However, I
was
poking around the knowledgebase articles on Avocent's website and I've come
across at least one article containing a pin-out diagram that differs and
shows DTR on another pin. I think I should really get the meter out again
&
test what's available on all pins, - I only tested the specific pin pair
that I believed to be GND & DTR yesterday...

Paul G.



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