IBM H80 Series manual Ring Detection, Terminal Emulators, Recovery Procedures, At&T

The sample modem configuration files included in this appendix do not support these modems, so custom configuration files are necessary. Anchor Automation 2400E is

an example of such a modem.

If you experience unexplainable performance problems that may be due to Xon/Xoff characters, it is recommended that you upgrade your modem.

Ring Detection

Most

modems

produce an interrupt request each time they detect a ring signal.

Some

modems

generate

an interrupt only

on

the

first

ring

signal

that

they

receive.

AT&T

DataPort

2001 is an example of such a modem.

The

Service

Processor

uses

the

ring

interrupt

request to

count

the

number

of

rings

when Ring Indicate Power-On (RIPO) is enabled. If your modem produces an

interrupt

on

only the first ring, set Ring Indicate Power-On to

start

on the

first ring.

Otherwise,

you can choose

to

start

Ring

Indicate

Power-On on

any

ring

count.

Terminal Emulators

The Service Processor is compatible with simple ASCII terminals, and therefore compatible with most emulators. When a remote session is handed off from the Service Processor to the operating system, agreement between terminal emulators becomes important.

The	server's		operating system		will have	some built-in terminal emulators. You may
also	have	a	commercially	available terminal emulation. It is important that the local
and	host	computers select the			same or	compatible terminal emulators	so that the key
assignments		and responses		match,	ensuring	successful communications and	control.

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

Recovery Procedures

Situations

such

as line

noises

and

power

surges can sometimes

cause

your

modem

to

enter

an undefined state. When it is being used

for

dial-in, dial-out or

ring indica

power-on, your

modem is initialized each time one

of these actions is expected. If

one

of

these

environmental

conditions

occur

after

your

modem has been initialized, it

might be

necessary

to

recover

your

modem

to

a

known

state.

If

your

modem

communicates

correctly

with

remote

users, it is probably in control. It

may be wise to occasionally

change

some

of

the

functional

settings

and

then

change

them

back,

just for

the sense

of

security

that

the

modem

is communicating,

and to

ensure

it

has

been

initialized

recently.

182 RS/6000 Enterprise Server Model H80 Series User's Guide