找一些相关的资料看看。
+++ 转换Modem 到指令状态。
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AT Commands
A Answer Command
Bn Communications Options
D Dial Command
En Select Command Character Echo Option
Hn Control The Switchhook
I0 Identify The Product Code
I2 Perform ROM Checksum Test
I7 Version Number
Ln Select Speaker Volume Level
Mn Select Speaker Function Option
Nn Select Negotiate Handshake Option
On Go Online Command
P Select Pulse Dialing Method
Qn Select Result Code Option
Sn= Write To An S-Register
Sn? Read An S-Register
T Select Tone Dialing Method
Vn Select Response Format Option
Wn Select Extended Result Code
Xn Select Call Progress Option
Yn Select Long Space Disconnect Option
Zn Perform Soft Reset
&An Select Originate/Answer Role For Autoanswer
&Cn Select Data Carrier Detect Option
&Dn Select Data Terminal Ready Option
&F Load Factory Default Profile
&Gn Select Guard Tone Option
&Kn Select Flow ConTDol Option
&Pn Select Pulse Dialing Parameters
&Qn Select Communications Mode Option
&Rn Select RTS/CTS Option
&Sn Select Data Set Ready Option
&T0 Terminate Test In Process
&T1 Initiate Local Analog Loopback
&T3 Perform Local Digital Loopback
&T4 Enable Granting Of RDL Requests
&T5 Deny Granting Of RDL Requests
&T6 Initiate Remote Digital Loopback
&T7 Initiate RDL With Self Test
&T8 Local Loopback With Self Test
&T19 Perform RTS/CTS Cable Test
&Un Disable TDellis Coding
&V View Configuration Profiles
&Wn Store Active Profile
&Xn Select Sync TDansmit Clock Source
&Yn Select Stored Profile For Hard Reset
&Zn= Store Telephone Number
, Perform Pause
= Write To An S-Register
? Read An S-Register
P Select Pulse Dialing
T Tone
S-Registers
S0 Ring After Which To Answer
S1 Ring Count
S2 Hayes Escape Character
S3 Carriage Return Character
S4 Line Feed Character
S5 Backspace Character
S6 Wait Before Blind Dialing
S7 Wait For Carrier
S8 Pause Time For Comma
S9 Carrier Recovery Time
S10 Lost Carrier Hang Up Delay
S11 DTMF Dialing Speed
S12 Hayes Escape Guard Time
S16 Test in Progress
S18 Modem Test Timer
S19 AutoSync Options
S25 Detect DTD Change
S26 RTS To CTS Delay Interval
S30 Inactivity Timeout
S31 XON Character
S32 XOFF Character
S36 Negotiation Failure TDeatment
S37 Desired DCE Line Speed
S38 Hang-up Timeout
S43 Current Line Speed
S44 Framing Technique
S46 Protocol/Compression Selection
S48 Feature Negotiation Action
S49 Buffer Low Limit
S50 Buffer High Limit
S70 Maximum Number of ReTDansmissions
S73 No Activity Timeout
S82 Break Selection
S86 Connection Failure Cause Code
S91 Select Dial-up Line TDansmit Level
S95 Extended Result Code Bit Map
S97 V.32 Late Connecting Handshake Timing
S105 Frame Size
S108 Signal Quality Selector
S109 Carrier Speed Selector
S110 V.32/V.32 bis Selector
S113 Calling Tone ConTDol
S121 Use of DTD
S141 Detection Phase Timer
S142 Online Character Format
S144 Autobaud Speed Group Selection