X-Authentication-Warning:	delorie.com: mail set sender to geda-user-bounces using -f
X-Recipient:	geda-user AT delorie DOT com
DKIM-Signature:	v=1; a=rsa-sha256; c=relaxed/relaxed;
	d=gmail.com; s=20120113;
	h=x-received:mime-version:from:date:message-id:subject:to
	:content-type;
	bh=94gPz+9Lc6B/LKxFJEz1iLn4bt36agB1ROQ4sNjNhV4=;
	b=htDhL9D1OVm9sVEZv9mwyjxL7la+PYD4dg2GE9vzG3+oqF6Zk2MBjUngNBczFPiWqL
	HP/01S2Qdm9ZddHvjAnbRw4+GHG9WoUmuVR7u6rOadWpI095xgd7vbgvWqHS65utL1Td
	k77XBuAUP74wiPI8itOTdbkyN9szwowTSbI/1eBO4ZfKZcBDzOmuB6aW1gm1MAz5nIf9
	gF1zFRnXoxeziyjtbotAAaCGQ7lAJoAXiG0nddmthGwoSrqLmXuU1h9FqQwA3eKBEQTk
	/T6KcoR84EWCComGwhlpNwqewZSOXFml6S5jxwZKut//SbI+QbJIFvmYGVhWfnytFDUS
	B2Jg==
X-Received:	by 10.58.181.201 with SMTP id dy9mr7367251vec.34.1362366882042;
	Sun, 03 Mar 2013 19:14:42 -0800 (PST)
MIME-Version:	1.0
From:	Patrick Doyle <wpdster AT gmail DOT com>
Date:	Sun, 3 Mar 2013 22:14:22 -0500
Message-ID:	<CAF_dkJDQxMRbY9EOS0MpmkOY5aqJ+T+DwO1Y+njUmVtOHKdMog@mail.gmail.com>
Subject:	[geda-user] Unterminated logic signals
To:	geda-user AT delorie DOT com
Reply-To:	geda-user AT delorie DOT com

--047d7b5d88230edda304d710c225
Content-Type: text/plain; charset=ISO-8859-1

Hello Experts!
I have a question for you...

I have a PCB I purchased from a vendor that has a 15 pin connector on it,
of which only 8 pins have defined functions.  (The functions of the other 7
pins are undefined by the manufacturer of the board and may or may not be
connected to logic on their board.  I have asked to what those pins are
connected, but haven't heard anything back yet).  Of the 8 pins with
defined functions, I use only 7.  I have a cable drawing that specifies
which 7 pins should be connected at each end of the cable.

The problem is, our manufacturing guys built (or allowed a 3rd party to
build) cables with all 15  pins in the connector populated.  At the other
end, they just cut the unused 8 wires and populated the connector with the
7 signals I use.

I am trying to decide whether I need to tell our manufacturing guys to
rework the cables or not.  How much do you think it matters that there
might be digital logic on the PCB driving signals down those unused wires
in my cable?  The cable itself is shielded, but I wonder what sort of cross
talk the unterminated signals might cause.  (I also worry a little bit
about the clipped ends shorting together, but for the purpose of this
question, I'm going to assume (ha ha) that they insulated each end after
they clipped it).

What do you folks think?

--wpd

--047d7b5d88230edda304d710c225
Content-Type: text/html; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable

Hello Experts!<div>I have a question for you...</div><div><br></div><div>I =
have a PCB I purchased from a vendor that has a 15 pin connector on it, of =
which only 8 pins have defined functions. =A0(The functions of the other 7 =
pins are undefined by the manufacturer of the board and may or may not be c=
onnected to logic on their board. =A0I have asked to what those pins are co=
nnected, but haven&#39;t heard anything back yet). =A0Of the 8 pins with de=
fined functions, I use only 7. =A0I have a cable drawing that specifies whi=
ch 7 pins should be connected at each end of the cable.</div>

<div><br></div><div>The problem is, our manufacturing guys built (or allowe=
d a 3rd party to build) cables with all 15 =A0pins in the connector populat=
ed. =A0At the other end, they just cut the unused 8 wires and populated the=
 connector with the 7 signals I use.</div>

<div><br></div><div>I am trying to decide whether I need to tell our manufa=
cturing guys to rework the cables or not. =A0How much do you think it matte=
rs that there might be digital logic on the PCB driving signals down those =
unused wires in my cable? =A0The cable itself is shielded, but I wonder wha=
t sort of cross talk the unterminated signals might cause. =A0(I also worry=
 a little bit about the clipped ends shorting together, but for the purpose=
 of this question, I&#39;m going to assume (ha ha) that they insulated each=
 end after they clipped it).</div>

<div><br></div><div>What do you folks think?</div><div><br></div><div>--wpd=
</div><div><br></div>

--047d7b5d88230edda304d710c225--

- Raw text -