Scott, About 99% of fax machines and chips produced after 1990 have CNG. Rockwell supplied 96% of fax chips since then. They still have about 90% of the market. Prior to 1990 Rockwell supplied about 99% of the fax modules and very few had CNG. I don't know the exact numbers. It is difficult to get exact numbers. I have been assuming 100% with CNG for the last 5 years. The main problem is a fax sent manually. Most machines allow manual operation and CNG is not sent in this mode. Call Diverters have a problem with manually sent fax. The other problem is old fax machines are not replaced until they break or there's a need for plain paper.
Hope this helps. Regards, Duane Marcroft Telecom Consultant On Tue, 19 Nov 1996, Scott Roleson wrote: > > Hello TREG'ers, > > I'm trying to get a handle on the number of FAX machines that do not generate > the 1100 Hz calling tone. Can anyone enlighten me or vector me to a resource? > > Calling tone is the method used by most FAX/telephone switches to detect if > an incoming call is a FAX call or a voice call, but some FAX machines don't > produce them, in part because the T.30 standard doesn't (or didn't) require > this tone. I believe there was an effort to make this a requirement, but > I'm not sure if this came to be or not. > > I've heard anecdotally that about 5% of the existing FAX machines today do > not produce calling tone, but I have no way to confirm this number. > > Any info? > > -- Scott Roleson > > ----------------------------------------------------------------------- > Scott Roleson, PE | Internet: [email protected] > EMC & Telecom Engineer | http://www.WP.com/SRoleson > San Diego Division MS 8-60 | Telephone: +1-619-655-4809 > Hewlett-Packard Company | FAX: +1-619-655-5931 > 16399 W. Bernardo Drive | Amateur Radio: KC7CJ > San Diego, CA 92127-1899 USA | Any opinions are my own, not HP's. > ----------------------------------------------------------------------- > > >
