Multi-Tech Systems Modem Module MT3334SMI - 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
frame data 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