Grason Merril, system operator of CMS Annapolis has begun to
institute what he calls a tele-tutor program. To make it more
useful, he has done some research to find away to enable smooth
switching from data transmition to voice and back. THis may be
very useful to some other system operators and may be interesting
for others to try out this procedure. Many people don't even
realize that they can send their Hayes compatible modem commands
after typing +++.
ERON

VOICE/DATA TOGGLING ON CMS ANNAPOLIS

INTRODUCTION

Two sequences of "AT" commands have been worked out which enable
voice/data toggling between CMS Annapolis and a user having a
Hayes compatible modem. This is very useful as an adjunct to
"chat mode"
communications, especially when tutoring a student as in the
TELE-TUTORING project. The instructions must be followed ac-
curately to be successful.

INITIAL CONDITIONS

The initial conditions presume that the student has logged on,
called up a lesson program, encountered a problem and asked for a
chat by typing C.
The tutor has responded by using OA B to shift to the "chat"
mode.

DATA TO VOICE SEQUENCE

1. Tutor type "Goto voice".
2. Both pick up their phones and listen throughout this sequence
and, of course, when talking.
3. Tutor type +++ (no
4. Student type +++ (no
5. Tutor type ATH
6. Student type ATH

This sequence causes each modem to retain its phone line con-
nection, return to the command state and stop sending its carrier
tone. Silence is the signal to talk.

VOICE TO DATA SEQUENCE

1. Tutor and student agree, by voice, to return to data (chat)
mode.
2. Tutor types ATA , calling out the letters as typed.
3. Within 30 seconds, student types ATD , calling out the
letters as typed.
4. When both carrier tones are heard, the phones must be im-
mediately returned to their cradles and data communications can
be resumed in the chat mode.
5. Tutor may then use OA B to return the student to the lesson
plan.

NOTES

1. Whenever the modems are connected to the phone line for data
communications they must be sending DIFFERENT tones. If they are
the same, they will "scream" back and forth.
2. During these sequences, tones and other odd noises will be
heard both in the phones and from the modem and some garbage may
be displayed.
Not to worry, no harm will result. In fact they are useful in
timing the sequences, once they are learned.
3. The command +++ must always be preceeded and followed by a
pause of one second or more to distinguish it from a data input.

Grayson Merrill, Sysop, 09-24-88.