Black Box MD1641A Manuale Utente

Entering 

automatically sets the modem’s speed to match the speed

of the computer or terminal, and also sets the modem’s parity. 

The AT characters alert the modem that a command follows. The AT
Command can also be used to clear the command buffer, by simply
typing 

and hitting RETURN.

The letter 

in a command causes the modem to dial the numbers

immediately following it (e.g., 

). You have a choice 

of either pulse (

) or tone (

) dialing methods.

The Modem responds with “CONNECT” on your video display after the
number is dialed and a connection signal is detected (since the Modem
defaults to Enhanced V.34/V.42/V.42bis, the actual response is
"CONNECT LAPM COMPRESSED”), if the Series II Modem “connects”
with a similar modem (see section 5.3 Result Code Summary). The
modem is now in “On-Line” mode, and is ready to communicate with a
host site. 

If no connection signal is detected within 45 seconds (this time period
can be adjusted by S-Register S7), the Modem goes On Hook/hangs up
and returns to Command mode. At this point, your video displays “NO
CARRIER”.

Enter 

to Hang Up On-Line (bring modem on-hook), and

terminate the modem's On-Line mode. At this point, your video
displays “OK”. 

In addition to the call originating capabilities, the Modem can also
automatically answer incoming calls. You need not be present. You can,
however, control the situation by configuring the modem to either
answer or not to answer, or to answer after a specified number of rings.
This is done by setting the value of S-Register S0 (modem defaults to
automatically answer an incoming call after one ring). Refer to
Chapter 6

for S-Register details.