Richard Luckhurst wrote:
I am setting up a redhat 7.2 box with a netcomm Mega I modem
on ttyS0 and I am trying to get mgetty working. I have used all the
defaults and mgetty is starting from inittab OK. When I try to dial into
the machine the modem is always off hook. I have tried a couple of
modems to make sure they are OK and they work fine. Any ideas
would be appreciated
Hi Richard,
To protect the punters your modem won't answer calls
by default. You'll need to send it an
AT S0=2
command, which will instuct the modem to answer on the
second ring (some modems will refuse a command to answer
on the first ring, as one way of meeting ACA requirements).
You'll probably also need to make the RS-232 flow control and
status lines work correctly.
AT &K3 CTS/RTS hardware flow control. Stops characters
being lost.
AT &C1 Data Carrier Detect status follows calling modem status.
Modem sets DCD=0 when no caller, sets DCD=1 after called
has connected (and modem speed negotiation has succeeded).
AT &D2 Data Terminal Ready status controls call acceptance.
PC sets DTR=1 when waiting for a call and during a
call. PC sets DTR=0 to hang up on a caller and prepare
the modem to accept another call. Linux sets DTR=1
when mgetty starts and sets DTR=0 when the user types
"logout".
There are probably other commands you want to issue as well,
but these are the basics.
mgetty is aware of the Hayes AT command set. If you use another
getty program you'll need to make the modem into a 'dumb' modem.
If you're doing this to implement serial console, then you've
barely touched the surface. See
http://www.tldp.org/HOWTO/Remote-Serial-Console-HOWTO/
If you're doing this just to support a remote command-line
dialin then you're are done.
--
SLUG - Sydney Linux User's Group - http://slug.org.au/
More Info: http://lists.slug.org.au/listinfo/slug
