V.22 bis Modem with AT Commands
CMX866
©
2008 CML Microsystems Plc
17
D/866/5
1.5.4
AT Command and Register Set
1.5.4.1 AT Command and S-Register Summary
AT Command
Parameters
Function
Default
A
Answer Command - Answer and establish a connection when off-hook
A/
Re-execute last command
Bn
n = 0..9
Select Communications Standard
n=0
Dn ... n
n = 0..9, A..D, *,# Dial Command - DTMF dials the subsequent Directory Number
or DTn ... n
,
Dial Command Modifier - Delay during dialling - time in S8 register
!
Dial Command Modifier- Send a line break - time in S29 register
;
Dial Command Modifier - command mode after dialling, no handshake
DL
Dial Command - Redial last number
En
n = 0,1
Command echo, 0=off, 1=on
n=1
Hn
n = 0,1
Switch Hook Control, 0=on-hook, 1=off-hook
n=0
In
n = 0
Identification - Returns the modem's product identification
Nn
n = 0,1
V.22bis Fallback to V.22 option, 0=none, 1=automatic n=1
O
Go online in Data mode (from Command mode)
Qn
n = 0,1
Enable(n=0)/Disable(n=1) return of modem result codes
n=0
RO
Execute V.23 or Bell 202 turnaround if enabled (see S14 and S24)
then go online in Data mode
Sn?
n = 0..29
S-Register "n" Read - Display specified S Register contents
Sn=x
n = 0..29
S-Register "n" Write - Write to specified S Register
Vn
n =0,1
Return result codes as numbers (n=0) or words (n=1)
n=0
Xn
n = 0..3
Calling and Response Characteristics
n=3
Z
Restore factory profile for CMX866
&Cn
n = 0,1
DCD always on (n=0) or DCD follows carrier (n=1)
n=1
&Dn
n= 0..2
DTR signal procedure
n=2
&Gn
n = 0..2
Guard Tone Select - Disable (n=0), Enable 550Hz (n=1) or 1800Hz (n=2)
n=0
&Tn
n = 0,3..6
User accessible Loopback Tests and Diagnostics
n=0
&V
Returns current configuration
&Zn
n = 0,1
'Zero-Power' state (n=0) or Powersave state (n=1)
@Rn?
n = 00..FF
DSP Register "n" Read - Display specified DSP Register contents
@Rn=x
n = 00..FF
DSP Register "n" Write - Write to specified DSP Register
S Registers
Parameters Function
Default
S0 0…255
Number of rings before answering, 0 = Auto-answer disabled
2
S1
0…255
Number of rings received
0
S2
0-127
Escape character value
+
S3
0-127
Carriage return character value
CR
S4
0-127
Line feed character value
LF
S5
0-127
Backspace character value
BS
S6
2…255
Waiting time in seconds for dial tone or before blind dialling
4s
S7
2…255
Maximum waiting time in seconds for carrier
50s
S8
0...255
Pause time in seconds for "," dial modifier
2s
S9 1...255
Reserved
S10
1…255
Lost carrier to hang up delay in units of 100ms
700ms