From:	MERC::"uunet!DRYCAS.CLUB.CC.CMU.EDU!synful+vmsnet-errors"  9-JUL-1992 09:42:43.24
To:	vmsnet@DRYCAS.CLUB.CC.CMU.EDU
CC:	
Subj:	Modem hangup

I have noticed, as soon as I have installed DECUS UUCP (1.3), that
users could only very difficulty connect to the Trailblazer Modem used
by uucp.

I think I have found out the reason, and somebody else could be
interested in it:

In page A-3 of the User Guide, a value of 90 sec is recommended for
register S7 "wait for carrier"; in dial script disl.tbgspoof, a value
of 90000 is given in state 'dialnumber' for 'ctime', that is the
maximum time to wait for a carrier. 

Only after this value is set, the script dials. The result is that, if
the modem does not sense the carrier, the script timeout expires the
first, when the modem is still waiting. When at last the modem timeout
also expires, it tries to output a NO CARRIER string, but as the
script is no longer waiting, the modem hangs and nobody can connect to
it from the telephone line side.

Moreover, if the connection succeeds, when it has to be regularly
dropped the modem also tries to output a NO CARRIER string, but if, as
stated at end of paragraph 6.6.3 'Hangup scripts', a hangup script is
not provided, tha same situation occurs.

I have put 20 seconds more in the script timeout than in the other and
have written a hangup mini-script as follows

	zero
	flush
wakemodem:
	count
	ifgtr	cantwake	4
	send	AT\r
	timeout	wakemodem	2000
	expect	turnoff0	OK

turnoff0:
	success

cantwake:
	logerr	Hangup: No OK from modem
	failed


It seems that now it works better.
------------------------------------------------------------------
Alberto Meregalli, SIC                         tel. +39 2 2125 249
Centro Elettrotecnico Sperimentale Italiano    fax  +39 2 2125 520
Via Rubattino, 54 - I 21034 Milano

meregalli%cesi@relay.iunet.it
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