[alt.fax] Class 1 and Class 2 standards

sl@van-bc.wimsey.bc.ca (Stuart Lynne) (10/11/90)

I just received some news from Joe Decuir, chairman of TR29.2 on availability 
of the Class 1 and Class 2 proposed fax standards.


>1. EIA-578, Class 1
>
>SP-2188 has been approved by EDEC for publication as EIA-578. ANSI approval
>is expected by 10/19/90. EIA publications expects to have it for sale by
>11/1/90, for $15. 
>
>2. SP-2388, Class 2
>
>SP-2388 can be bought, from EIA Standard Sales Dept, as "BSR/EIA-SP2388" for
>$28. 
>

For further information contact the EIA at:

	2001 Eye Stree, N.W.
	Washington, D.C. 20006
	202-457-4900


Class 1 suggests a very simple interface where almost all of the work to
implement the fax emulation (the infamous T.30 state machine) is done in the
host. Basically commands to send/receive HDLC data, and send/receive fax data 
are defined. You get to do the rest.

Class 2 provides a more complicated interace where the fax emulation is done
in the modem, but controlled by the host. Approximatetly 40 commands are
defined to control the modems behaviour, transfer data, and control the
emulation of the fax protocols. You have to know enough of the T.30 state
machine to control it, but you don't have to actually implement it at the
host level. [While this sounds hard, it's simple enough that procomm can
send or receive a fax using this protocol with a script and one additional
program to send/receive the fax images. The extra program is apparantly only
required due to procomm being unable to pass null bytes.]

-- 
Stuart Lynne	Unifax Communications Inc.
		...!van-bc!sl 604-937-7532(voice)     	sl@wimsey.bc.ca