Honeywell CNI2 User Manual

CNI2
O
perating and Installation
Guide
113
AT MODEM EMULATION M
ODE
For this discussion the symbol
<cr>
indicates an ASCII control
character called “car
riage return”
and is represented by a single value (byte) of 13 decimal or 0D hex.
For this discussion the symbol
<lf
>
indicates an ASCII control character called “line feed” and is
represented by a single value (byte) of 10 decimal or 0A hex.
NOTE
If th
e CNI2
will respond to AT modem commands in ALL modes of operation.
If you have a serial device attached to the CNI2’s serial port it is likely that the device is
expecting to communicate with an AT
-
compatible modem. The acronym “AT” means
“attention”.
AT modem commands always start with the ASCII characters “AT” or ”at” followed
by other characters that define specific operations. The final character of a command string is
always a carriage return
(<cr>).
Upon
completion of a command the
modem se
nds back a response in one of two formats,
either “terse” or “verbose”. Terse messages (also called “non
-
verbose”
or “numeric”
) are often
one to two ASCII numbers followed
by a
<cr>. Verbose messages are readable ASCII
messages preceded and followed by a
<cr><lf>
combination
. For example when an incoming
call is detected the verbose message will be “<cr><lf>RING<cr><lf>” whereas the terse version
is simply “2<cr>”.
These are the typical responses that the CNI will return to the remote device:
Terse
Response
(
Note
-
1
)
Verbose
Response
(Note
-
2)
DESCRIPTION
0
OK
Accepted, no error
1
CONNECT
Connected with remote modem
2
RING
Incoming call
3
NO CARRIER
Connection with remote modem is lost
4
ERROR
Command error
Note
-
1:
Terse (non
-
verbose) resp
onses always followed by one carriage return
<cr>.
Note
-
2:
Verbose responses always preceded
and
followed by one carriage return
<cr>
and on
e
line feed <lf>.
Typical CNI2 “AT” Responses
The remote device may issue commands that were important to the ori
ginal modem but not to
the CNI
2
. In these cases the CNI
2
will return a standard response such as “OK” to these
commands. Other commands are meaningful and the
CNI2
will act upon them. The following is
a list of these commands. The
CNI2
defaults to cert
ain settings until programmed otherwise.
ATV (response type) Command
ATV, ATV0
: This instructs the CNI2 to return “terse” (non
-
verbose or numeric) result codes

Honeywell CNI2 Specifications

General

Brand	Honeywell
Model	CNI2
Category	Recording Equipment
Language	English