Multi-Tech Systems Modem Module MT3334SMI User Manual
Page 38

ModemModule Developer’s Guide
MT3334SMI
38
Table 3-2. Single-Page Class 1 Transmit Example
Action by
Action by
Command
Respone
Local Modem
Remote PC
AT+FCLASS=1
OK
Set Class 1
ATD
Dial and send CNG
Answers
Look for V.21
Sends CED, V.21
Detect flags
Sends HDLC flags
CONNECT
Detect flags
Get CSI
Send CSI packet
Send NSF packet
OK
AT+FRH=3
CONNECT Detect flags
Get CSI
Send CSI packet
Get FCS
OK
Accept FCS
Check FCS
AT+FRH=3
CONNECT
Detect flags
Get DIS
Send DIS packet
Get CRC
OK
Accept FCS Check FCS
AT+FRH=3
NO CARRIER
Detect loss of carrier
Drop carrier
AT+FTH=3
Send V.21 carrier
Detect carrier
CONNECT
Send flags
Detect flags
Send TSI frame
Get TSI frame
Send FCS
CONNECT
Send flags
Send DCS frame
Send DCS frame
Send FCS, flags
OK
Drop carrier
AT+FTS=8; +FTM=96
Wait 80 msec
CONNECT
Send V.29 carrier
Detect carrier
Send TCF data
Get TCF data
OK
Drop carrier
AT+FRH=3
Detect carrier
Send V.21 carrier
CONNECT
Detect flags
Send flags
Get CFR frame
Send CFR frame
Check FCS
Send CRC
OK
Accept FCS
AT+FRH=3
NO CARRIER
Detect loss of carrier
Drop carrier
AT+FTM=96
CONNECT
Send V.29 carrier
Detect carrier
Send page data
Receive page
OK
Drop carrier
AT+FTS=8; +FTH=3
Wait 80 msec
Send V.21 carrier
Detects carrier
CONNECT
Send flags
Detects flags
Send EOP frame
Receives EOP
Send FCS
OK
Drop carrier
(Final frame)
AT+FRH=3
Detect carrier
Send V.21 carrier
CONNECT
Detect flags
Send flags
Get MCF frame
Send MCF frame
Check FCS Send FCS
OK
Accept FCS
AT+FRH=3
NO CARRIER
Detect carrier loss
Drop carrier
AT+FTH=3
Send V.21 carrier
Detects carrier
CONNECT
Send flags
Detect flags
Send DCN frame
Receives DCN
Send FCS
OK
Drop carrier
ATH0
OK
Hang up
Hangup