AT Cmd Function Mode Value Setting
3 LAPM or MNP (V42 Detection Phase)
4 MNP Only
6 Initiate Synchronous Access Mode when connected
Originate Fallback EC Mode DFV 0 EC Optional, fallback to Normal Mode
1 EC Optional, fallback to Direct Mode
2 EC Required (LAPM or MNP)
3 EC Required (LAPM Only)
4 EC Required (MNP Only)
Answer Fallback EC Mode DFV 0 Direct Mode
1 Normal Mode
2 EC Optional, fallback to Normal Mode
3 EC Optional, fallback to Direct Mode
+ES 4 EC Required (LAPM or MNP)
(cont.) 5 EC Required (LAPM Only)
6 EC Required (MNP Only)
8 Initiate Synchronous Access Mode when connected
+ESA Transparent Sub-Mode Idle DFV 0 DCE transmits 8 bit SYN sequence on idle.
Framed Sub-Mode Idle DFV 0 DCE transmits HDLC flags on idle.
Framed Sub-Mode Underrun DFV 0 DCE transmits abort on underrun in middle of frame.
or Overrun 1 DCE transmits a flag on underrun in middle of frame,
notifies DTE of underrun or overrun.
Half Duplex Control N/A - Not Used
CRC Type DFV 0 CRC generation and checking is disabled
1 In framed sub-Mode 16 bit CRC is generated by the DCE
in Tx direction and checked by the DCE in RX direction.
NRZI Control DFV 0 NRZI encoding and decoding is disabled
+ETBM Disc Buff Dly - Pending TD DFV 0 Discard buffered data and disconnect
1 Attempt until all data delivered, ignore timer
2 Attempt until all data is delivered or timer expires
Disc Buff Dly - Pending RD DFV 0 Discard buffered data and disconnect
1 Attempt until all data delivered, ignore timer
2 Attempt until all data is delivered or timer expires
Disc Buff Dly - Timer DFV 0 - 255 Delivery timer in seconds (default is 0)
+FCLASS Fax/Modem Mode DFV 0 Data Mode
1 Fax Class 1 Mode
8 Voice Mode
+FLO Fax Flow Control DFV 0 None
1 XON/XOFF
2 RTS/CTS
+FMI? Report Manufacturer ID DFV - -
+FMM? Report Modem ID DFV - -
+FMR? Report Revision # DFV - -
+FPR Fax DTE Rate DFV 0 Autobaud
+FRH Receive HDLC Mode F 3 V.21 at 300 bps
24 V.27ter at 2400 bps
48 V.27ter at 4800 bps
72 V.29 at 7200 bps
73 V.17 at 7200 bps with long train time
74 V.17 at 7200 bps with short train time
96 V.29 at 9600 bps
97 V.17 at 9600 bps with long train time
98 V.17 at 9600 bps with short train time
121 V.17 at 12000 bps with long train time
122 V.17 at 912000 bps with short train time