No subject


Mon Aug 3 13:59:58 MDT 2009


the state of the serial control lines

RTS - Request To Send
CTS - Clear To Send
DTR - Data Terminal Ready

Could this be related to the problem?

-Nate

On Tue, Sep 8, 2009 at 3:30 AM, Michael Tandy <m.j.tandy at warwick.ac.uk>wrote:

> OK, so:
>
> 1. It worked in spring but has stopped doing so and
> 2. The data all arrives at once when you start hyperterminal.
>
> Is it possible you're using a different serial cable to connect to the
> device, compared to the one you were using in spring?
>
> If so, the issue might be hardware flow control - that is, your device
> might be buffering data because it can't transmit it until your
> computer sets 'DTR' or 'RTS' or something like that.
>
> One way of bypassing hardware flow control is by using cables which
> cross over certain wires so that the right signals are always being
> sent; it's possible your old cable had these connections but your
> current cable doesn't have them. If you can find the old cable, you
> could put it back in and see if that fixes things?
>
>
> 2009/9/8 Nathaniel S. Parsons <nsp25 at cornell.edu>:
> > (Sorry if this is a double post, but I sent my original message without
> > subscribing, and since this is an urgent problem, I thought I'd resend
> after
> > subscribing to bypass the moderator limbo zone)
> >
> > Hi all,
> >
> > I've asked my question on StackOverflow already, so rather than
> copy-paste
> > the question here, I'd like to redirect you there.
> >
> > Short version, I am no longer able to receive anything over RS-232 with
> > RXTX, but other programs work fine. I'm definitely sending things,
> because
> > when I connect with a different program, all the responses to the
> commands I
> > sent via RXTX arrive all at once.
> >
> > Everything was fine in the spring, so what could have happened? Windows
> > update?
> >
> > -Nate
> >
> > _______________________________________________
> > Rxtx mailing list
> > Rxtx at qbang.org
> > http://mailman.qbang.org/mailman/listinfo/rxtx
> >
> >
> _______________________________________________
> Rxtx mailing list
> Rxtx at qbang.org
> http://mailman.qbang.org/mailman/listinfo/rxtx
>

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Thanks for the response. I&#39;ll try to get to the electronics store tomor=
row to get more serial cables, even if it isn&#39;t the problem.<br><br>I a=
m using a different serial cable than I was in the spring. It&#39;s actuall=
y a Male/Female cable with a female-female adapter since the old cables are=
n&#39;t around anymore. The hardware&#39;s manual says nothing except to us=
e a &quot;Straight cable&quot; but I figured that if it worked in HyperTerm=
inal, it should work in RXTX, right?<br>

<br>Anyways, I&#39;ve also noticed some things that are different between H=
yperTerminal, RXTX, and a separate program I found that communicates with t=
he device (but doesn&#39;t do what I want, which is why I&#39;m rolling my =
own program)<br>

<br>HyperTerminal - set to no flow control, but Serial Port Monitor&#39;s R=
TS and DTR indicators are green<br>Other program - not sure what settings i=
t thinks it&#39;s using, but only SPM&#39;s RTS indicator is green<br>
RXTX - no matter what flow control I set, only SPM&#39;s CTS and DTR indica=
tors are on.<br>
<br>From Serial Port Monitor&#39;s help files (paraphrased): the indicators=
 display the state of the serial control lines<br><br>RTS - Request To Send=
<br>CTS - Clear To Send<br>DTR - Data Terminal Ready<br><br>Could this be r=
elated to the problem? <br>

<br>-Nate<br><br><div class=3D"gmail_quote">On Tue, Sep 8, 2009 at 3:30 AM,=
 Michael Tandy <span dir=3D"ltr">&lt;<a href=3D"mailto:m.j.tandy at warwick.ac=
.uk">m.j.tandy at warwick.ac.uk</a>&gt;</span> wrote:<br><blockquote class=3D"=
gmail_quote" style=3D"border-left: 1px solid rgb(204, 204, 204); margin: 0p=
t 0pt 0pt 0.8ex; padding-left: 1ex;">

OK, so:<br>
<br>
1. It worked in spring but has stopped doing so and<br>
2. The data all arrives at once when you start hyperterminal.<br>
<br>
Is it possible you&#39;re using a different serial cable to connect to the<=
br>
device, compared to the one you were using in spring?<br>
<br>
If so, the issue might be hardware flow control - that is, your device<br>
might be buffering data because it can&#39;t transmit it until your<br>
computer sets &#39;DTR&#39; or &#39;RTS&#39; or something like that.<br>
<br>
One way of bypassing hardware flow control is by using cables which<br>
cross over certain wires so that the right signals are always being<br>
sent; it&#39;s possible your old cable had these connections but your<br>
current cable doesn&#39;t have them. If you can find the old cable, you<br>
could put it back in and see if that fixes things?<br>
<br>
<br>
2009/9/8 Nathaniel S. Parsons &lt;<a href=3D"mailto:nsp25 at cornell.edu">nsp2=
5 at cornell.edu</a>&gt;:<br>
<div><div></div><div class=3D"h5">&gt; (Sorry if this is a double post, but=
 I sent my original message without<br>
&gt; subscribing, and since this is an urgent problem, I thought I&#39;d re=
send after<br>
&gt; subscribing to bypass the moderator limbo zone)<br>
&gt;<br>
&gt; Hi all,<br>
&gt;<br>
&gt; I&#39;ve asked my question on StackOverflow already, so rather than co=
py-paste<br>
&gt; the question here, I&#39;d like to redirect you there.<br>
&gt;<br>
&gt; Short version, I am no longer able to receive anything over RS-232 wit=
h<br>
&gt; RXTX, but other programs work fine. I&#39;m definitely sending things,=
 because<br>
&gt; when I connect with a different program, all the responses to the comm=
ands I<br>
&gt; sent via RXTX arrive all at once.<br>
&gt;<br>
&gt; Everything was fine in the spring, so what could have happened? Window=
s<br>
&gt; update?<br>
&gt;<br>
&gt; -Nate<br>
&gt;<br>
</div></div>&gt; _______________________________________________<br>
&gt; Rxtx mailing list<br>
&gt; <a href=3D"mailto:Rxtx at qbang.org">Rxtx at qbang.org</a><br>
&gt; <a href=3D"http://mailman.qbang.org/mailman/listinfo/rxtx" target=3D"_=
blank">http://mailman.qbang.org/mailman/listinfo/rxtx</a><br>
&gt;<br>
&gt;<br>
_______________________________________________<br>
Rxtx mailing list<br>
<a href=3D"mailto:Rxtx at qbang.org">Rxtx at qbang.org</a><br>
<a href=3D"http://mailman.qbang.org/mailman/listinfo/rxtx" target=3D"_blank=
">http://mailman.qbang.org/mailman/listinfo/rxtx</a><br>
</blockquote></div><br>

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