Class 1.0,80 modems

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Hi,

Klaus Rathmann wrote:
> this is what i have noticed in Rockwell's 
> RCV288ACi/SVD Modem Designer's Guide,
> where 
> 	SVD means 	Simultaneous Voice and Data.
> 
> 
> VOICEVIEW MODE ( +FCLASS=80 ) 

Aaah. Thanks for that information, it's very good to know.

> All these SVD-modems lack support of fax class 2,2.0 capability. 

Yep, seems so.

> By the way, this is what my ELSA-Modem and any usefull modem reports on 
> at+fclass=?		-> 0,1,2,2.0,8
> And this the newer ELSA 56K Modem should report to you
> at+fclass=?		-> 0,1,1.0,2,2.0,8

Does it do that? This would be a good thing. (Now, we only have to make
the ELSA fax mode *reliable*, and then we have a new modem recommendation).

> first base on Rockwell RCV288DPi chipset with 1Mbit EPROM 
> and second on new RCVDL56ACF/SP chipset with very large 2Mbit FlashRom
> whitout any SVD capability.
> 
> Fax Standards: 
> Class 2		(SP-2388)
> Class 2.0	(TIA/EIA-592) 
> Class 1		(TIA/EIA-578)

This is "old news" :-) - but good that it's there.

> Class 1.0	(ITU-T T.31) <-- Never seen this before !	
> 				 What is going on here ? 

ITU is trying to standardize about everything :-) -- basically it's
similar to class 1, same commands and everything, but the timing issues
seem to be specified more precisely. I didn't really cross-check class 1
and class 1.0 yet to find out all the nasty differences...

One very interesting thing is the "ITU T.31 amendment 1", which specifies
class 1.0 fax using V.34 modulation -- and which is, de facto, something
completely new. Begone the AT+FTH=... commands, begone CONNECT or OK
responses, everything done with <DLE><code> now... *very* interesting
indeed.

[Yes, I'm studying class 1.* docs right now, and yes, I'm going to
implement it, at least for testing, but *no*, I have *no* idea whether
it will work, or when it will be available -- class 1 is HARD work, you
need to understand all of T.30, which is 167 pages of cross references to
other ITU standards...]

gert

> On 28 Nov 1997, Gert Doering wrote:
> 
> > Hi,
> > 
> > Bo wrote:
> > > >Can someone with a Rockwell modem check whether AT+FCLASS=? returns
> > > >"1.0"?
> > > 
> > > Hi Gert,
> > > I have tested two modems with a Rockwell chip. They are a Legato E-SVD
> > > and a LASAT Safire (if brand names are interesting at all). Here's the
> > > output:
> > > 
> > > AT+FCLASS=?
> > > 0,1,1.0,80
> > 
> > Interesting indeed!
> > 
> > > So, it seems they do exist :-)
> > 
> > Yes!
> > 
> > Now, what's "class 80"?
> > 
> > gert
> > 
> > -- 
> > USENET is *not* the non-clickable part of WWW!
> >          //www.muc.de/~gert/
> > Gert Doering - Munich, Germany      gert@greenie.muc.de
> > fax: +49-89-35655025    gert.doering@physik.tu-muenchen.de
> > 
> > 
> > 
> 
> 
> 


-- 
USENET is *not* the non-clickable part of WWW!
           //www.muc.de/~gert/
Gert Doering - Munich, Germany      gert@greenie.muc.de
fax: +49-89-35655025    gert.doering@physik.tu-muenchen.de
.