docs/69225: PATCH-Serial comms chapter has wrong acronym for Transmit Data

[Warren Block]

On Sun, 18 Jul 2004, Marc Fonvieille wrote:

> On Sun, Jul 18, 2004 at 12:00:52PM +0000, Giorgos Keramidas wrote:
> >  On 2004-07-17 22:40, Warren Block <wblock at wonkity.com> wrote:
> >  > --- /usr/doc/en_US.ISO8859-1/books/handbook/serialcomms/chapter.sgml	Sat Jul 17 06:22:19 2004
> >  > +++ chapter.sgml	Sat Jul 17 22:37:04 2004
> >  > @@ -978,11 +978,11 @@
> >  >
> >  >  	<itemizedlist>
> >  >  	  <listitem>
> >  > -	    <para>Transmitted Data (<acronym>SD</acronym>)</para>
> >  > +	    <para>Transmit Data (<acronym>TD</acronym>)</para>
> >  >  	  </listitem>
> >
> >  Actually, the LED that shows transmit line activity in my modem is
> >  labelled "SD".  Perhaps, we should change the description text to "Sent
> >  Data" instead?
>
> SD is on the modem, the text is talking about a RS232 cable: "A standard
> RS-232C serial cable should suffice as long as all of the normal signals
> are wired:"
>
> I'd change SD for TD which is the correct term in our case (or TxD, but
> in this case RD must be changed for RxD).  TD is the data transmitted by
> the DTE (our computer) to the DCE (modem), RD is data to DTE from DCE.
> These descriptions come from a time where half duplex was common.
> s/Transmitted/Transmit/ etc. is not mandatory, in fact both versions are
> used.

You're right, but I'd never seen the "Transmitted" form until a web 
search this morning.

> So I'd keep the description but I'd s/SD/TD which is correct.

Now that I look at it more, TxD/RxD are used earlier in the chapter, and 
are the more correct way to go.  I think these are probably how they are 
listed in the EIA spec.

As for the description changes, I suggest those changes for consistency 
with the other pin descriptions.  If you have Transmitted Data, you 
should also have Data Terminal Readied, Carrier Detected, Signal 
Grounded (okay, maybe not that one 8-).

-Warren Block * Rapid City, South Dakota USA