[net.dcom] How to hang up?

ken@models.UUCP (12/08/83)

We have a Racal-Vadic 3451 auto-dial modem which we use to dial out.
It's attached to a tty port (we're running 4.1bsd) on an Emulex CS21/F
(like a DMF32); all lines are configured for "modem". The "/etc/ttys
entry is "03ttyxx". To dial out, we say
	cu -a /dev/null -l /dev/ttyxx -s 1200
After it says "Connected", we type ^E return and talk to the modem. Generally
we talk to non-UNIX systems this way.

The problem is that when we're done, we can disconnect (~.) in software,
but the modem doesn't hang up; the remote system doesn't drop DTR or DSR
or whatever it's supposed to drop. Is there a way to tell it to hang up that
1) doesn't require kludging the cu source and 2) doesn't require you to
be superuser?

Ken Winston
harpo!rocky2!cubsvax!models!ken

akp@isrnix.UUCP (12/12/83)

#R:models:-10700:isrnix:5000001:000:716
isrnix!akp    Dec 11 15:37:00 1983

Chances are, the problem is in the switch settings within the modem, or
somewhere like it. Most modems are equipped with a switch to select the
response to DTR dropping low. If the switch is one way, DTR is ignored, and
you can't use it to hang up. With the switch the other way, DTR is obeyed,
and when you drop it (your ~. should do that) the modem hangs up the phone.
Some incompetents at Southwest Peripherals, Inc. in Phoenix fiddled
with the switches on 20 VenTel modems, when the factory settings were
correct, and caused a week of troubleshooting.  If there are no switches
on (in) the Racal-Vadic modem, try somewhere on your rs232 interface card.
							-- Allan Pratt
				...decvax!ihnp4!iuvax!isrnix!akp

wls@astrovax.UUCP (William L. Sebok) (12/12/83)

One (unfortunately) has to cut a jumper in the VADIC 3451 to get it to control
Data Terminal Ready (i.e. to hang up).  The modem comes from the factory with
the jumper uncut (and DTR held always high).
-- 
Bill Sebok			Princeton University, Astrophysics
{allegra,akgua,burl,cbosgd,decvax,ihnp4,kpno,princeton}!astrovax!wls

lmc@denelcor.UUCP (Lyle McElhaney) (12/12/83)

In our Vadic 3451, the DTRon is a DIP switch.
-- 

			Lyle McElhaney
			...(hao,nbires,brl-bmd,csu-cs)!denelcor!lmc
			(303) 337-7900 x261