Mail Archives: geda-user/2013/03/04/11:59:48
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:in-reply-to:references:from:date:message-id
|
| :subject:to:content-type;
|
| bh=ep0o92BK/85kM5Ne4EBxS5GLHdZY8vMzIhsUofz8aes=;
|
| b=xvxfiUImlAEIhTl3labtnfgPQlIPkqBQhMQg63gPC141izHdAw2ZDnoC6NHxiME35w
|
| sl+nbUmnNA8kG0+HDmhht6/famsqSG3uSsSagfHF72XKEFtbc17/pWaz5p0+5ys3/l77
|
| xJxyRpVaTXxqfJ6IYWfXtMbnjYmBMZKkhdLDeuzMPaS45C2JxDG9eqrMelur0a2OhuyO
|
| TGb+ZUu7+pi4tKVpfv/Q8X7q6lw6pdlDuBrvMl4oULTitYnZ5q62NyKuBTw8x4E6h7/f
|
| LQE9jHJfkWxRTlnVipwL3cx69a4///1FSA0imFfviqbmFQCnxTFaANXbgffIXPyEevmC
|
| 1b9g==
|
X-Received: | by 10.52.36.194 with SMTP id s2mr7119107vdj.119.1362416347677;
|
| Mon, 04 Mar 2013 08:59:07 -0800 (PST)
|
MIME-Version: | 1.0
|
In-Reply-To: | <CAOP4iL0QUhegh6wvp_3amYmqRANHt7DEH+b=aj8CZx=0k+-JcQ@mail.gmail.com>
|
References: | <CAF_dkJDQxMRbY9EOS0MpmkOY5aqJ+T+DwO1Y+njUmVtOHKdMog AT mail DOT gmail DOT com>
|
| <CAOP4iL0QUhegh6wvp_3amYmqRANHt7DEH+b=aj8CZx=0k+-JcQ AT mail DOT gmail DOT com>
|
From: | Patrick Doyle <wpdster AT gmail DOT com>
|
Date: | Mon, 4 Mar 2013 11:58:46 -0500
|
Message-ID: | <CAF_dkJCLJzc7F9HXhxMqkFOA1JxvwCfHTXAGDTF6ty-kXf=bzA@mail.gmail.com>
|
Subject: | Re: [geda-user] Unterminated logic signals
|
To: | geda-user AT delorie DOT com
|
Reply-To: | geda-user AT delorie DOT com
|
Errors-To: | nobody AT delorie DOT com
|
X-Mailing-List: | geda-user AT delorie DOT com
|
X-Unsubscribes-To: | listserv AT delorie DOT com
|
--20cf307c9fc0708cd304d71c464f
Content-Type: text/plain; charset=ISO-8859-1
On Mon, Mar 4, 2013 at 10:23 AM, Ouabache Designworks <z3qmtr45 AT gmail DOT com>wrote:
>
>
> On Sun, Mar 3, 2013 at 7:14 PM, Patrick Doyle <wpdster AT gmail DOT com> wrote:
>
>> 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
>>
>>
>
> If you don't fix it and you have any problems at all then you will waste a
> lot of time proving that the problems are not due to these extra wires
> before you move on to find the real issues.
>
>
> John Eaton
>
>
>
> Hi everybody, thanks for the comments and advice. I think that John's
reply sums up my thoughts on the matter best.
--wpd
--20cf307c9fc0708cd304d71c464f
Content-Type: text/html; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable
<br><div class=3D"gmail_quote">On Mon, Mar 4, 2013 at 10:23 AM, Ouabache De=
signworks <span dir=3D"ltr"><<a href=3D"mailto:z3qmtr45 AT gmail DOT com" targe=
t=3D"_blank">z3qmtr45 AT gmail DOT com</a>></span> wrote:<br><blockquote class=
=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padd=
ing-left:1ex">
<br><br><div class=3D"gmail_quote"><div><div class=3D"h5">On Sun, Mar 3, 20=
13 at 7:14 PM, Patrick Doyle <span dir=3D"ltr"><<a href=3D"mailto:wpdste=
r AT gmail DOT com" target=3D"_blank">wpdster AT gmail DOT com</a>></span> wrote:<br><=
blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1px=
#ccc solid;padding-left:1ex">
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'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'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></blockquote></div></div><div><br><br>If you don't=
fix it and you have any problems at all then you will waste a lot of time =
proving that the problems are not due to these extra wires before you move =
on to find the real issues.<br>
<br><br>John Eaton<br><br>=A0<br></div></div><br>
</blockquote></div>Hi everybody, thanks for the comments and advice. =A0I t=
hink that John's reply sums up my thoughts on the matter best.<div><br>=
</div><div>--wpd</div><div><br></div>
--20cf307c9fc0708cd304d71c464f--
- Raw text -