Model 820 Technical Reference Manual
B-35
820
Phone Dialing Procedure
The Model 820 dialing process is as follows:
Step 1
The Model 820 recognizes an exceedance or low
memory condition.
Step 2
The Model 820 asks the modem to dial the phone
number.
Example:
820: ATDT 1-555-
1234(Enter)
Step 3
The modem informs the Model 820 that a connec-
tion has been made. The Model 820 modifies its
baud rate to that of the connected modem. If the con-
nection is unsuccessful, the procedure is retried in 4
min.
Modem: 10(Enter)
Step 4
The Model 820 sends the following announcement:
“
820: 820A0123:001:2
” (enter), where (0123) is the
Model 820’s serial number, (001) is the monitor
number entered, and (2) is a flag: 1-Alarm 2-
Exceedance 4-Low Memory. More than one of these
can be set at a time, in which case x is the sum of all
set flags.
Step 5
The Model 820 awaits a response code, which
should be: “820 A0123:11111111” (enter), where
(0123) is the Model 820’s serial number and
(11111111) is the Lock Combination (parameter 28)
which is required whether or not the Model 820 is
currently locked. If the response is incorrect, the
announcement is resent. Four chances are given to
respond correctly. A “3 cr” sequence will cause the
Model 820 to hang up.
Step 6
When a correct response is received, the Model 820
indicates it is ready to send data when requested
with “820:Ready”(enter).
Model 820 Answering Procedure
Step 1
The modem informs the Model 820 that a connec-
tion has been requested; that is, the phone is ringing.
Modem:2 (enter)
Step 2
The Model 820 answers the phone.
820: ATA (enter)
