At commands – Telenetics 56 User Manual
Page 159
AT Commands
Page 151
Examples
Examples of calling (transmitting) and answering (receiving) one page using fax class 1
commands are shown in Table A-20 and Table A-21, respectively. The examples show
the interchange between the DTE and the modem for various cases. Comments are
included to explain how to handle various situations. Commands and responses are in
upper case (e.g., AT+FRH=3) and comments are in lower case. All streams of data
denoted by <..frame> are terminated by the
Table A-20. Fax Class 1 Calling Sequence (Transmitting a Single Page)
DTE Commands
Modem
Responses
Local Modem Action
Remote Station
Action
Notes
AT+FCLASS=1
OK
Set Class 1
ATDT
CONNECT
OK
Dial and send CNG
Look for V.21
Detect flags
Answer
send CED, V.21
Send HDLC
flags
Send NSF frame
AT+FRH=3
implied by dialing with
+FCLASS=1.0
AT+FRH=3
CONNECT
OK
Detect flags
get CSI
get FCS
accept FCS
send CSI frame
check FCS
Frame status OK
AT+FRH=3
CONNECT
OK
Detect flags
get DIS
get FCS
accept FCS
send DIS frame
check FCS
DTE must detect final
frame bit to anticipate
loss of carrier
AT+FRH=3
NO CARRIER
detect loss-of-carrier
drop carrier
AT+FRH=3
CONNECT
CONNECT
OK
send V.21 carrier
send flags
send TSI frame
send FCS
send flags
send DCS frame
send FCS, flags
drop carrier
detect carrier
detect flags
get TSI frame
get DCS frame
Final frame bit clear tells
the modem to expect
another frame. Final
frame bit set tells the
modem not to expect
another frame
AT+FTS=8;
+FTM=96
CONNECT
OK
wait 80 ms
send V.29 carrier
send TCF data
drop carrier
detect carrier
get TCF data
AT+FRH=3
CONNECT
OK
detect carrier
detect flags
get CFR frame
check FCS
accept FCS
send V.21
carrier
send flags
get CRF frame
send FCS
Final frame bit set.
frame OK
AT+FRH=3
NO CARRIER
detect loss-of-carrier
drop carrier
r
AT+FTM=96
CONNECT
OK
send V.29 carrier
send page data
drop carrier
detect carrier
receive page
AT+FTS=8;
+FRH=3
wait 80 ms
send V.21 carrier
send flags
detect carrier
detect flags