IBM RS/6000 manual Recovery Procedures, Seamless Transfer of a Modem Session, Dtr

The	server's operating system will have			some built-in terminal emulators. You
also	have	a commercially	available terminal emulation. It is important that t
and	host computers select the same or compatible terminal emulators so the
assignments		and responses	will match. This	will assure successful communications
and	control.

For best formatting, choose line wrap in your terminal emulator setup.

Recovery Procedures

Line noises, power surges, etc., can sometimes cause your modem to enter undefined state. When it is being used for dial-in, dial-out or ring indi your modem is initialized each time one of these actions is expected.

environmental			conditions occur after your modem has been						initialized, it	may
essary		to	recover your modem to a				known	state.
If	your		modem	communicates properly			with	remote users,	it is probably	in
may	be wise to occasionally change						some of the functional settings and th
them	back,		just	for	the sense	of	security that the		modem is communicatin
assure		it	has	been	initialized	recently.

Another strategy, particularly if your system is difficult to access phy protect it with an Uninterruptable Power Source (UPS) and a phone-line surg tector.

In case recovery becomes necessary, your system should be shut down as fully as possible. Disconnect the power cable and press the power button capacitance while power is disconnected. Disconnect and reconnect modem pow then reconnect system power to allow complete reinitialization of your syst

Seamless Transfer of a Modem Session

There are about as many modem command variations as there are modems. The sample modem configuration files have been written to capture the largest workable modem settings.

The	modem	command &Dn		(where 'n' is a number) generally				sets	the modem
response to the Data Terminal Ready						(DTR)	signal from	the	server's serial
desired		response	is	that the	modem	will hold a connection while DTR is e
and	drop the connection when DTR is					released. This is the mechanism by w
server hangs up on			a	connection	under	normal	conditions.

C-6RS/6000 Enterprise Server Model H Series User's Guide