ATCommands
Zoltrix Modem Manual For
Zoltrix 14,400 Fax/33,600 V.34 Modem
The commands listed in this document are for Zoltrix Modems based on Rockwell International's ACI V.34+ chipset. To determine if your modem uses this chipset send the following command from the “Terminal Mode” of a communication program:
ATI6 [ENTER]
If your modem responds with ERROR, you do not have this chipset!
This document is intended for your modem if your Modem responds with something simular to the following:
RC288DPi Rev 04BC
Your Zoltrix MODEM has been pre-set at the factory for optimum performance. All defaults are set to allow the modem to negotiate the best possible connection with highest quality, data compression, and error correction.
The INIT string used at the factory and stored into the modem is as follows:
AT&F&C1&D2S95=3
Because the modem was initialized at the factory, you could use an initialization (INIT) string of:
ATZ
Note: This command resets the modem to the stored settings. If the
settings have been changed by software or manually, this INIT string may not work correctly.
You could change the INIT string in all of your software packages to either of the two previous examples. The first example is the best to use because some software may change the values stored in the modem.
If you want to custom configure your stored profiles, we suggest that you always start out with an AT&F&C1&D2 before customizing other commands. This string will reset the modem to the factory defaults as well as reset some other basic settings.
If modem performance suffers after modifying settings, send the INIT string above (AT&F&C1&D2) to the modem.
PERFORMANCE ISSUES
To get optimum performance from your Zoltrix MODEM, the phone line quality over which you are transmitting and receiving must be reliable and relatively free of “noise”.
LIMITING THE MODEMS TOP SPEED
If you experience problems connecting to slower modems (2400 or 1200bps), you may need to instruct your modem to limit the top speed to attempt. You may also need to limit the top spped the modem attempts to something less than 33,600bps, even when calling another 33,600 modem, because of the line noise in your area. If you don't, you may experience “garbage” or a “NO CARRIER” message. This should not be neccassary in most cases, but, there are some 2400bps and 1200bps or even 9600bps modems you may not connect to without using one of the following methods:
Note: Rockwell has changed the method of limiting the top speed. There is now
one method that should be used in most cases. The older method of using the N0 command and setting S37 to a value will still work for speeds under 14,400, but the S37 settings above 14,400 that were used by the V.FC chipset will not function. The Fn command has also been eliminated and replaced with the +MS= command.
1. Use the +MS= command. AT+MS=11,1,19200,24000 will set the modem to use
V.34 modulation, automode detection, with 19200bps as the lowest connection rate acceptable, and 24,400 as the highest connection rate attempted. AT+MS=11,1,2400,24000 will set the modem to use V.34 modulation, automode detection, with 2400bps as the lowest connection rate acceptable, and 24,000 as the highest connection rate attempted. Note: See the +MS= command for more details and examples.
2. Use the combination of the N0 command along with setting S37 to the
proper value to limit the modems connection speed attempted.
3. Use the N0 command and set your software to the connection rate
desired. Note: This is not the desired method to use if you are making an error-correction connection with compression! The softwares "BAUD" rate should be at least twice, and preferably four, times the Carrier rate established. Otherwise you will get no benifits from the compression. Transfers will actually be slower than if a non-compression connection was established. You also cannot set software to all the connection rates that are supported by the V.34 28,800 modem.
CUSTOM INIT STRINGS WITH DESCRIPTIONS OF MODEM CONFIGURATIONS
MODEL: ZOLTRIX V.34 33,600 (V.34,V.FC,V.32bis,V.42bis,MNP) 1) V.42bis Auto
Init String: AT&F&C1&D2W2 This configuration should be the only configuration required to make all possible connections. The Modem will first attempt a V.42bis connection, if the remote Modem does not support V.42bis, the Zoltrix Modem will attempt an MNP5 connection, if the remote Modem does not support MNP5 the Zoltrix Modem will attempt an NORMAL connection (No error correction or compression). Because some Modems do not recognize the V.42bis handshaking sequence or you may want to make a special type of connection, we have added 15 possible connections types to ensure that the Zoltrix Modem will make a successful connection with all Modems.
2) V.42/MNP4 Auto
Init String: AT&F&C1&D2W2S46=136%C0 This configuration is the same as V.42bis Auto except that all compression is turned off (V.42bis and MNP5 disabled).
3) MNP5
Init String: AT&F&C1&D2W2S48=128 This configuration will bypass the V.42bis and V.42 negotiation and attempt MNP5 first. If the remote Modem does not support MNP5 the Zoltrix Modem will attempt an NORMAL connection (No error correction or compression). Use this selection if you know that the remote Modem is only a MNP Modem and does not support V.42/V.42bis.
4) MNP4
Init String: AT&F&C1&D2W2S48=128%C0 This configuration will bypass the V.42bis and V.42 negotiation and attempt MNP4 first. If the remote Modem does not support MNP4 the Zoltrix Modem will attempt an NORMAL connection (No error correction or compression). Use this selection if you know that the remote Modem is only a MNP Modem and does not support V.42/V.42bis. This selection turns off the MNP5 compression. MNP5 may actually slow down file transfers of compressed files, therefore you may want to turn MNP5 off but still want the error correction capabilities of MNP4.
5) NORMAL
Init String: AT&F&C1&D2&Q6W2 This configuration will not attempt V.42 or MNP but instead attempt a NORMAL connection. If you know that the remote Modem does not support V.42 or MNP, select this configuration type. This will actually speed up the hand-shaking process. Many non-error-correcting modems do not interpet the V.42 and MNP signals correctly. Using this selection will eliminate the problems seen when calling non-error-correcting modems.
Note: You may add additional commands to any of the preceeding INIT strings,
but it is recommended that you put the additional commands at the end of the INIT string.
BASIC AT COMMANDS
Command Description
AT Attention characters ATA Answer command ATA/ Re-Execute last command
CCITT or Bell B0 Selects CCITT operation at 300 or 1200bps. B1 Selects Bell operation at 300 or 1200bps.
Transmit Carrier Signal ATC0 Not supported. ATC1 Transmit carrier signal on.
ATD none Dial. (ATD followed by phone number)
Dial Modifiers
Dial Options Description
none Dial the "star" digit (tone dialing only)
none Dial the "pound" digit (tone dialing only)
L none Re-dial. P none Pulse (rotary) dial. 10 pulses per second. T none Touch tone dial (DTMF). W 1-255 sec Wait for dial-tone. Default is 50 seconds. , 0-255sec Pause. Default is 2 seconds. @ none Wait for quiet answer. none Initiate hook flash.
; none Return to command state after dialing. & none Wait for credit card dialing tone before continuing
with the dial string. If bong is not detected within the time specified by S7, the modem will abort the rest of the sequence, return on-hook, and generate an error mesage.
Command Echo ATE0 Disables echoing of the commands to the screen. ATE1 Enables echoing of the commands to the screen.
(default)
Disconnect (Hang-up) ATH0 Instructs modem to go on-hook. ATH1 Instructs modem to go off-hook.
Identification ATI0 Displays the product identification code. ATI1 Displays the checksum. ATI2 Displays ROM checksum as OK or ERROR. ATI3 Displays the firmware revision level. ATI6 Reports modem data pump and internal code revision.
Speaker volume ATL0 Off or low volume. ATL1 Low volume. (default) ATL2 Medium volume. ATL3 High volume.
Speaker control ATM0 Disables the modem speaker. ATM1 Turns speaker on until carrier has been detected. (default) ATM2 Instructs the modem speaker to stay on all of the time. ATM3 Enables speaker after dialing until connection is established.
Automode enable ATN0 Automode detection is disabled (equivalent to setting the
+MS<automode> subparameter to 0). A subsequent handshake will be conducted according to the contents of S37 or, if S37 is zero, according to the most recently sensed DTE speed.
ATN1 Automode detection is enabled (equivalent to setting the
+MS<automode> subparameter to 1). A subsequent handshake will be conducted according to the contents of S37 or, if S37 is zero, starting at 33,600 bps V.34. (Default)
Notes: 1. The Nn and S37=x commands override the +MS command settings. When the
N0 or N1 command is issued, the +MS subparameters are updated to reflect the Nn and S37 values (see +MS command and S37 register). For example: N1S37=10 updates the +MS command subparameters to reflect +MS=10,1,300,12000 N0S37=10 updates the +MS command subparameters to reflect +MS=10,0,300,12000
2. Use of the +MS command is recommended instead of the Nn and S37=x commands.
Nn and S37=x commands are supported for compatibility with existing communication software.
Return to on line state mode ATO0 Switches the modem from command mode to on-line mode after dropping
to command mode using the escape sequence (+++).
ATO1 Switches from command mode to on-line mode an initiates an
equalizer retrain sequence before returning to on-line mode.
Set Pulse Dial as default P This command forces pulse dialing until the next T dial modifier
or T command is received.
Mode responses ATQ0 Enables result codes to be issued to the screen. (default) ATQ1 Disables result codes to be issued to the screen. (Quiet mode)
Set Tone Dial as default T This command forces Tone dialing until the next P dial modifier
or P command is received.
Result code format ATV0 Numeric format. ATV1 Verbal format. (default)
Error correction message control ATW0 Error correction call progress not reported. (default) ATW1 Call progress reported. Enables CARRIER and PROTOCOL result codes. ATW2 Call progress not reported. Connect xxxx message
reports DCE speed (Carrier rate).
Extended result codes ATX0 Disables monitoring of busy tones unless forced otherwise
by country requirements; sends only OK, CONNECT, RING, NO CARRIER, ERROR and NO ANSWER result codes.
ATX1 Disables monitoring of busy tones unless forced otherwise by
country requirements; sends only OK, CONNECT, RING, NO CARRIER, ERROR, NO ANSWER and CONNECT XXXX result codes.
ATX2 Disables monitoring of busy tones unless forced otherwise by
country requirements; sends only OK, CONNECT, RING, NO CARRIER, ERROR, DIAL TONE, NO ANSWER and CONNECT XXXX result codes.
ATX3 Enables monitoring of busy tones; sends only OK, CONNECT, RING,
NO CARRIER, ERROR, NO DIALTONE, NO ANSWER and CONNECT XXXX.
ATX4 Enables monitoring of busy tones and sends all messages.
(default)
Control long space disconnect ATY0 Disables long space disconnect. (default) ATY1 Enables long space connect.
Soft reset and restore profile ATZ0 Restores stored profile 0. (default) ATZ1 Restores stored profile 1.
+++ Escape characters. The escape characters are known as +++.
They will switch from on-line mode to command mode while preserving the connection with the on line modem.
EXTENDED AT COMMANDS
Command Description
Data carrier detect (DCD) signal AT&C0 Forces DCD signal to be on at all times. (default) AT&C1 DCD on indicates presence of data carrier.
(REQUIRED BY MOST SOFTWARE)
Data terminal ready (DTR) signal. Interprets the ON to OFF transition of the DTR signal from the DTE according to the &Q settings.
AT&D0 &Q0,5,6. DTR ignored.
&Q1,4. Modem hangs up; auto answer not affected. &Q2,3. Modem hangs up; auto answer inhibited. (default)
AT&D1 &Q0,1,4-6. Asynchronous escape sequence.
&Q2,3. Modem hangs up; auto answer inhibited.
AT&D2 &Q0-6. Modem hangs up; auto answer inhibited. AT&D3 &Q0,1,4-6. Modem does a soft reset as if the ATZ
command were received; &Q2,3. Modem hangs up; auto answer inhibited.
AT&F Recalls factory defaults 0. Instructs the modem to load the
factory set parameters (these can NEVER change).
AT&F1 Recalls factory defaults 1.
Select Guard Tone AT&G0 Disables guard tone. (Default) AT&G1 Disables guard tone. AT&G2 Selects 1800hz guard tone.
Telephone Jack Control AT&J0 No function but included for compatibility. AT&J1 No function but included for compatibility.
DTE/Modem flow control AT&K0 Disable flow control. AT&K3 Enable RTS/CTS (default for data modem) AT&K4 Enable XON/XOFF. AT&K5 Enable transport XON/XOFF. AT&K6 Enable both RTS/CTS and XON/XOFF (default for FAX and Voice modes.)
Note on Flow Control. XON/XOFF is a software-based flow control method, using standard ASCII control characters to pause or resume data transmission. RTS/CTS pacing, a hardware-based method, uses an electrical signal. Signals are exchanged as follows:
RECEIVER TRANSMITTER CTS ON —————> START SENDING CTS ON ←————- RTS ON (ready to send) CTS OFF ————–> RTS OFF (stop sending)
Command Description
Select pulse dial make/break ratio AT&P0 Selects a make/break ratio of 39/61 at 10pps.
US and Canada. (default)
AT&P1 Selects a make/break ratio of 33/67 at 10pps.
UK and Hong Kong.
AT&P2 Same as 0 except at 20pps. AT&P3 Same as 1 except at 20pps.
Asynchronous mode AT&Q0 Direct Asynchronous mode. All “Error Correction” and
"Compression" protocols are turned off. This requires that the Softwares "BAUD" rate matches the Modems.
AT&Q5 Modem negotiates an error-corrected link. (default) AT&Q6 Selects asynchronous operation in normal mode.
(Speed Buffering allows software "BAUD" rate to be locked at a fixed rate.)
RTS/CTS Option AT&R0 In sync mode, CTS tracks the state of RTS; the RTS-to-CTS
delay is defined by S26. In async mode, CTS acts according to V.25bis handshake.
AT&R1 In sync mode,CTS is always ON (RTS transition are ignored).
In async mode, CTS will only drop if required by flow control. (Default)
Data Set Ready (DSR) signal AT&S0 Causes DSR signal to be active at all times. (default) AT&S1 Causes DSR signal to be active after answer tone has been
detected and inactive after the carrier has been lost.
Test and diagnostics The modem will perform selected test and diagnostic functions according to the parameter supplied. A test can be run only when in an asynchronous operation in non-error-correction mode. To terminate a test in progress, the escape sequence must be entered first, except for parameters 7 and 8. If S18 is non-zero, a test will terminate automatically after the time specified by S18 and display the OK message. AT&T0 Terminates any test in progress. AT&T1 Executes the local analog loopback test. AT&T3 Executes the local digital loopback test. AT&T4 Enables the modem to accept a request from a
remote mode for a digital loopback test. (default)
AT&T5 Instructs the modem to deny a request from a
remote modem for a digital loopback test.
AT&T6 Executes the remote digital loopback test. AT&T7 Executes the remote digital loopback test with a
self test.
AT&T8 Executes the remote analog loopback test with a
self test.
AT&V View current configuration and user profile. Following is an example of the resulting display:
ACTIVE PROFILE: B1 E1 L3 M1 N1 Q0 T V1 W2 X4 Y0 &C1 &D2 &G0 &J0 &K3 &Q5 &R1 &S0 &T5 &X0 &Y0 S00:000 S01:000 S02:043 S03:013 S04:010 S05:008 S06:002 S07:050 S08:002 S09:006 S10:014 S11:095 S12:050 S18:000 S25:005 S26:001 S36:007 S37:000 S38:020 S44:020 S46:138 S48:007 S95:003
STORED PROFILE 0: B1 E1 L3 M1 N1 Q0 T V1 W2 X4 Y0 &C1 &D2 &G0 &J0 &K3 &Q5 &R1 &S0 &T5 &X0 S00:000 S02:043 S06:002 S07:050 S08:002 S09:006 S10:014 S11:095 S12:050 S18:000 S36:007 S37:000 S40:104 S41:195 S46:138 S95:003
STORED PROFILE 1: B1 E1 L2 M1 N1 Q0 T V1 W0 X4 Y0 &C1 &D0 &G0 &J0 &K3 &Q5 &R1 &S0 &T4 &X0 S00:000 S02:043 S06:002 S07:050 S08:002 S09:006 S10:014 S11:095 S12:050 S18:000 S36:007 S37:000 S40:104 S41:195 S46:138 S95:000
TELEPHONE NUMBERS: 0= 1= 2= 3=
OK
Store user profile. Saves the current configuration into non-volatile RAM as one of two user profiles. AT&W0 Saves as user profile 0. AT&W1 Saves as user profile 1.
Designate default user profile AT&Y0 Selects user profile 0. AT&Y1 Selects user profile 1.
Stored phone number AT&Z=0 Stores a 36 digit dial string. AT&Z=1 Stores a 36 digit dial string. AT&Z=2 Stores a 36 digit dial string. AT&Z=3 Stores a 36 digit dial string.
MNP Operation
The Zoltrix V.34 28,800bps Modems supports all of the preceding classes. The following AT Commands apply to the MNP protocol. Many of the following commands may be overridden or perform the same function as other Extended AT Commands.
Default values are highlighted.
Maximum MNP Block Size. Use this command to transmit smaller blocks of data in a reliable data link connection.
AT\A0 set maximum block size to 64 characters. AT\A1 set maximum block size to 128 characters. (DEFAULT) AT\A2 set maximum block size to 192 characters. AT\A3 set maximum block size to 256 characters.
Transmit Break. When this command is entered during a non-MNP connection, a break signal is sent to the remote modem. The length of the break is 100 times the n parameter (1-9) in milliseconds. The default is 3. AT\B3 (DEFAULT)
Break Control. Determines the modem response when a BREAK is received from the DTE or the remote modem. The values of the parameters vary based on the three following conditions:
(1) When a break is received from the DTE during NORMAL or MNP mode:
AT\K0, 2, 4 modem enters command mode without sending a break
to the remote modem.
AT\K1 modem clears the terminal and modem buffers and
sends a break to the remote modem.
AT\K3 modem does not clear the buffers, but sends a
break to the remote modem.
AT\K5 modem sends a break to the remote modem in
sequence with any transmitted data. (DEFAULT)
(2) When a break is received from the remote modem during NORMAL mode:
AT\K0, 1 modem clears the terminal and modem buffers and
sends a break to the local DTE.
AT\K2, 3 modem does not clear the buffers but sends a break
to the local DTE.
AT\K4, 5 modem sends a break in sequence with any data
being buffered. (DEFAULT)
(3) When a break is received from the DTE during DIRECT MODE mode:
AT\K0,1,3 modem sends a break to the remote modem and enters
command mode.
AT\K2, 4, 5 modem sends a break to the remote modem. (DEFAULT)
Error Correction Operating Mode. Selects the operating mode the modem uses while connected.
AT\N0 NORMAL (speed buffering) mode. (Forces &Q6) AT\N1 DIRECT (pass-through) mode. (Forces &Q0) AT\N2 RELIABLE LINK mode. Specifies error correction
for the modem-to-modem connection. (Forces &Q5, S36=4, and S48=7.)
AT\N3 AUTO-RELIABLE LINK mode. Attempts error-correction
connection but will fall back to normal mode if unable to establish an MNP link. (Forces &Q5, S36=7, and S48=7.)
AT\N4 LAPM error correction mode. (Forces &Q5 and S48=0) AT\N5 MNP error correction mode. (Forces &Q5, S36=4, and S48=128.)
AT Commands for V.42/V.42bis
The following AT commands apply to the V.42/V.42bis protocol:
Compression Control. Determines whether or not modem will use data compression.
AT%C0 disables data compression AT%C1 enables MNP5 data compression negotiation AT%C2 enables V42bis data compression AT%C3 enables both V.42bis and MNP5 data compression
(DEFAULT)
Auto-retrain. Determines whether or not the modem automatically monitors the line quality and requests a retrain when necessary.
AT%E0 Disables line quality monitor auto-retrain.
(DEFAULT)
AT%E1 Enables line quality monitor auto-retrain. AT%E2 Enables line quality monitor auto retrain and auto
fall back/forward.
Report Received Signal Level.
AT%L 009 = -9 dBm, 010 = -10dBm, etc. all the way to 043
(-43 dBm)
AT%Q Line Signal Quality Line signal and noise are determined by the unit of measurement dBm (decibel referenced to one milliwatt). To arrive at a signal/noise ratio, the noise level is subtracted from signal level in dBm.
Report Line Signal Quality. Returns a “high-order” byte of the calculated EQM (“eye quality monitor”). When the value gets too high, the modem will automatically retrain if enabled by the AT%E1 command. The value for a normal connection ranges from 0 to 30 and approaches 127 for a progressively poorer connection. Returns an OK result code.
AT+MS Select Modulation This extended-format command selects the modulation, optionally enables or disables automode, and optionally specifies the lowest and highest connection rates using one to four subparameters. The command format is:
+MS=<mod>[,[<automode>][,[<min_rate>][,[<max_rate>]]]]<CR>
Notes: 1. For 14400 bps and lower speeds, the Nn command and S37 register can
alternatively be used, in which case the +MS subparameters will be modified to reflect the Nn and S37=x settings. Use of the Nn and S37=x commands is not recommended but is provided for compatibility with existing communication software. (S37 is not updated by the +MS command.)
2. Subparameters not entered(enter a comma only or <CR> to skip the last
subparameter) remain at their current values.
Reporting Selected Options
The modem can send a string of information to the DTE consisting of selected options using the following command:
+MS?
The response is:
<mod>,<automode>,<min_rate>,<max_rate>
For Example:
11,1,300,33600
Reporting Supported Options
The modem can send a string of information to the DTE consisting of supported options using the following command:
+MS=?
The response is:
(list of supported <mod> values),(list of supported <automode> values), (list of supported <min_rate> values), (list of supported <max_rate> values)
For Example:
(0,1,2,3,9,10,11,64,69,74),(0,1),(300-33600),(300-33600)
Subparameter Definitions
1. <mod> = A decimal number which specifies the prefered modulation (automode
enabled) or the modulation (automode disabled) to use in originating or answering a connection. The options are:
<mod> Modulation Possible Rates (bps) {see note 1}
0 V.21 300 1 V.22 1200 2 V.22bis 2400 or 1200 3 V.23 1200 {See note 2} 9 V.32 9600 or 4800
10 V.32bis 14400,12000,9600,7200, or 4800 11 V.34/V.34+ 33600,31200,28800,26400,24000,21600,19200,16800,
14400,12000,9600,7200,4800, or 2400
64 Bell 103 300 69 Bell 212 1200 74 V.FC 28800,26400,24000,21600,19200,16800, or 14400
Notes: 1. See optional <automode>,<min_rate>, and <max_rate> subparameters. 2. Not supported by Zoltrix V.34 Fax/Modem.
The modem may also automatically switch to another modulation (automode), subject to the following constraints:
a. The modem may not be able to automatically switch from the current
modulation (specified by <mod>) to some other modulation. For example, there is no standard way to automode from Bell 103 to V.23.
b. The DTE may disable automode operation (see <automode> below). c. The DTE may constrain the range of modulations available by specifying
the lowest and highest rates (see <min_rate> and <max_rate> below).
2. <automode> is an optional numeric value which enables or disables automatic modulation negotiation using V.8 or V.32bis Annex A. The options are:
<automode> Option Selected
0 Automode disabled 1 Automode enabled using V.8 or V.32 Annex A
The default value is 1, which enables automode. Note, however, there are modulations for which there is no automatic negotiation, e.g., Bell 212.
For <automode> = 0 (automode disabled, i.e., fixed modulation):
a. If <max_rate> is within the rates supported by the selected modulation,
the selected rate is that specified by <max_rate>. For example:
+MS=9,0,1200,4800 selects V.32 4800 bps fixed rate.
b. If <max_rate> is greater than the highest speed supported by the modulation
specified by <mod>, the starting rate is the highest rate supported by the selected modulation. For example:
+MS=9,0,2400,14400 selects V.32 at 9600 or 4800 bps.
c. To emulate issuance of the N0S37=x command sequence to select fixed mode
operation, specify the <max_rate> and <min_rate> both to be the same requested speed, and <mod> to be the modulation for that speed. For example:
+MS=11,0,16800,16800 selects V.34 16800 bps fixed mode (no comparable S37 command).
+MS=9,0,12000,12000 selects V.32bis 12000 bps fixed mode (same as N0S37=10)
For <automode> = 1 (automode enabled,
i.e. automatically selected speed and modulation):
The modem connects at the highest possible rate in accordance with V.8, or V.32bis Annex A if V.8 is not supported by the remote modem.
a. If <max_rate> is greater than the highest rate supported by the modulation
specified by <mod>, the modem automodes down from the highest rate of the selected modulation. For example:
+MS=10,1,1200,24000 selects automoding down from V.32bis 14400 bps.
b. To emulate issuance of the N1S37=x sequence command, specify the modulation
and the rate to start automoding down from using <mod> and <max_rate>, respectively. Set <min_rate> to 300 to allow automoding all the way down to V.21 300 bps. For example:
+MS=11,1,300,16800 selects automode starting at V.34 16800 bps (no comparable S37 command).
+MS=9,1,300,12000 selects automode starting at V.32bis 1200 bps (same as N1S37=10).
3. <min_rate> is an optional number which specifies the lowest rate at which
the modem may establish a connection. The value is decimal coded, in units of bps, e.g., 2400 specifies the lowest rate to be 2400 bps. The default is 300 for 300 bps.
4. <max_rate> is an optional number which specifies the highest rate at which
the modem may establish a conection. The value is decimal coded, in units of bps, e.g., 14400 specifies the highest rate to be 14400 bps. The default is 33600 for 33600 bps.
S-REGISTERS
This section defines the purpose of the modem registers, and sequentially lists the registers and describes their functions. These registers affect various operating characteristics and allow you to obtain information about the modem, as well as test the modem. The valid ranges for the registers are also included.
READING A REGISTER VALUE
You can inquire about the current value of these registers with the S? command. To read the current value of a register, type:
AT Sn? [ENTER],
where n is a register number.
To read the register values of S0 and S7, type
AT S0? S7? [ENTER].
The modem will display the first register value, a carriage return, the next register value, a carriage return, and OK or 0.
CHANGING A REGISTER VALUE
To change a register value, use the Sn command (ATSn=v), where n is a register number and v is the new value you want to assign to the register. Type:
AT S0=1 [ENTER]
to have the modem automatically answer on the firt ring.
S0 Auto Answer
Range: 0-255 Unit:Ring This register holds the number of rings the modem will wait for before answering the phone if a ring is detected. It is usually set in the software. If this register is set to zero, the modem will not answer the phone.
S1 Ring Count
Range: 0-255 Unit:Ring This register counts the number of rings detected on the line. It is cleared if a ring is not detected over an eight second time period. If the register value equals the value contained in S0, the modem will answer the phone.
S2 Escape Code Character
Range: 0-127 Unit:ASCII This register contains the ASCII value of the character used as the Escape Code. The default of 043 is the "+".
S3 Carriage Return Character
Range: 0-127 Unit:ASCII This register contains the ASCII value of the character used to send a carriage return. The default value of 013 is the normal carriage return.
S4 Line Feed Character
Range: 0-127 Unit:ASCII This register contains the ASCII value of the character used to send a line feed. The default value of 010 is the normal line feed.
S5 Backspace Character
Range: 0-32 Unit:ASCII This register contains the ASCII value of the character used to back space. The default value of 008 is the normal backspace.
S6 Wait for Dial Tone
Range: 2-255 Unit:Seconds This register stores the number of seconds the modem will wait between going off-hook and starting the dial sequence. The minimum time is two seconds, even if the register value is lower.
S7 Wait for Carrier
Range: 0-255 Unit:Seconds This register stores the amount of time the modem will wait for the carrier signal from the remote modem. If a carrier is not received in this time, the modem will hang up and send the NO CARRIER result code.
S8 Pause Time for Carrier
Range: 0-255 Unit:Seconds The value of this register determines how long the modem should pause when it sees a comma in the dialing string.
S9 Carrier Detect Response Time
Range: 1-255 Unit:1/10 Second This register contains the time required for the modem to recognize the receive character from the remote modem, and turn on DCD (Data Carrier Detect).
S10 Lost Carrier to Hangup Delay
Range: 1-255 Unit:1/10 Second This register value determines the amount of time from when the modem recognizes a loss of carrier to when it will hang up. If this value is set lower than the value contained in S9, a loss of carrier will always result in a disconnection.
S11 Duration/Spacing DTMF
Range: 50-255 Unit:1/1000 Second This register contains the duration of and the spacing between DTMF (touch tone) dialing characters.
S12 Escape Prompt Delay (EDP)
Range: 0-255 Unit:1/50 Second Defines the maximum period, in fiftieths of a second, allowed between receipt of the last character of the three escape character sequence from the DTE and sending of the OK result code to the DTE. If any characters are detected during this time, the OK will not be sent. Note that sending of the OK result code does not affect entry into command mode.
S13 Not Used
S14 BIT MAPPED OPTIONS Value Description Command Bit 0 Used Internally Bit 1 Command Echo 0 Disabled E0
1 Enabled E1
Bit 2 Result Codes 0 Enabled Q0
1 Disabled Q1
Bit 3 Result Code Type 0 Numeric V0
1 Verbal V1
Bit 4 Used Internally Bit 5 Dial Method 0 Tone T
1 Pulse P
Bit 6 Used Internally Bit 7 Originate/Answer 0 Answer A
1 Originate D
S15 Not Used
S16 Modem Test Options Value Description Command Bit 0 Local Analog Loopback 0 Disabled
1 Enabled &T1
Bit 1 Not Used Bit 2 Local Digital Loopback 0 Disabled
1 Enabled &T3
Bit 3 Status Bit 0 Loopback Off
1 In Progress
Bit 4 Initiate Remote 0 Disabled
Digital Loopback 1 Enabled &T6
Bit 5 Remote Digital Loopback 0 Disabled
With Error Count 1 Enabled &T7
Bit 6 Local Analog Loopback 0 Disabled
With Self Test 1 Enabled &T8
Bit 7 Not Used
S17 Not Used
S18 Test Timer
Range: 0-255 Unit: Seconds This register value determines how long a diagnostic test will be allowed to run before being aborted. With the value set to zero, (the default), the test timer is disabled and the test must be terminated by issuing an &T0 or H command. When S18 is non-zero, the modem returns the OK message upon test termination.
S19 Not Used
S20 Not Used
S21 Bit Mapped Options Value Description Command Bit 0 Telephone Jack 0 RJ11 &J0
1 RJ12 &J1
Bit 1 Not Used Bit 2 RTS/CTS 0 CTS/RTS &R0
1 CTS always true &R1
Bit 3,4 DTR 0 Ignore DTR &D0
1 Modem to Command State &D1 on the ON-to-OFF DTR transition 2 Modem hangs up &D2 on the ON-to-OFF DTR transition 3 Initialization state &D3 on the ON-to-OFF DTR transition
Bit 5 DCD 0 Always on &C0
1 Follows Carrier &C1
Bit 6 Not Used Bit 7 Long Space Disconnect 0 Disabled Y0
1 Enabled Y1
S22 Bit Mapped Options Value Description Command Bit 0,1 Speaker Volume 0 Low L0
1 Low L1 2 Medium L2 3 High L3
Bit 2,3 Speaker Control 0 Speaker off M0
1 On until carier M1 detected 2 Always on M2 3 On until carrier M3 detected,but off while dialing
Bit 4, Result Codes 0 See X0 command X0
5,6 4 See X1 command X1 5 See X2 command X2 6 See X3 command X3 7 See X4 command X4
Bit 7 Make/Break Ratio 0 39:61 (US) &P0
1 33:67 (UK) &P1
S23 Bit Mapped Options Value Description Command Bit 0 Obey request from remote 0 Disabled &T5
modem for remote digital 1 Enabled &T4 loopback test
Bit 1, Assumed DTE Rate 0 300 bps
2,3 1 600 bps 2 1200bps 3 2400bps 4 4800bps 5 9600bps 6 19200bps
Bit 4,5 Parity Option 0 Even
1 Space 2 Odd 3 Mark
Bit 6,7 Guard Tones 0 Disabled &G0
1 Disabled &G1 2 1800 Hz &G2
S24 Not Used
S25 Async DTR Delay
Range: 0-255 Unit:1/100 Second The modem will ignore a change in the DTR status for the time interval that is defined in this register when in the asynchronous mode.
S26 Sync RTS/CTS Delay
Range: 0-255 Unit:1/100 Second The modem will ignore a change in the RTS/CTS status for the time interval that is defined in this register, when in the synchronous mode.
S27 Bit Mapped Options Bits Description Command
3 1 0
Bit 0,1 Operation Mode 0 0 0 See &Q0 &M0 or &Q0
3 0 0 1 See &Q1 &M1 or &Q1 0 1 0 See &Q2 &M2 or &Q3 0 1 1 See &Q3 &M3 or &Q3 1 0 0 See &Q4 &Q4 1 0 1 See &Q5 &Q5 1 1 0 See &Q6 &Q6
Bit 2 Line Type 0 Dial up &L0
1 Leased line &L1
Bit 4,5 Transmit Clock 0 Internal &X0
1 External &X1 2 Slave &X2
Bit 6 Service Type 0 CCITT B0
1 Bell 212A B1
Bit 7 Not Used
S28 Not Used
S29 FLASH DIAL MODIFIER TIME
Range: 0-255 Unit:1/100 Second Sets the length of time that the modem will go off-hook when it encounters the flash (!) dial modifier in the dial string.
S30 DISCONNECT INACTIVITY TIMER
Range: 0-255 Unit: 10 seconds Sets the length of time that the modem will stay online before disconnecting when no data is sent or received. In
error-correction mode, any data transmitted or received will reset the timer. In other modes, any data transmitted will reset the timer. The timer is inoperative in synchronous mode.
S31 Bit Mapped Options. Bits Description Command Bit 0 Not Used Bit 1 Speed detection 0 Disabled N0
1 Enabled N1
Bit 2,3 Progress Messages 0 DTE speed W0
1 Full reporting W1 2 DCE speed W2
Bit 4-7 Not Used
S32 XON Character
Range: 0-255 Unit: ASCII Sets the value of the XON character. Default value is 17.
S33 XOFF Character
Range: 0-255 Unit: ASCII Sets the value of the XOFF character. Default value is 19.
S36 V.42 NEGOTIATION FAILURE TREATMENT
Range: 0-7 Unit: Decimal This register is read when the S48 register equals 128 or if an attempted V.42 connection fails. These fallback options are initiated immediately upon connection if S48=128.
S36=0 Modem Disconnects. S36=1 Modem stays on-line and a Direct mode connection is established. S36=2 Reserved. S36=3 Modem stays on-line and a Normal mode connection is established. S36=4 An MNP connection is attempted and if fails, the modem disconnects. S36=5 An MNP connection is attempted and if fails, a Direct mode
connection is established.
S36=6 Reserved. S36=7 An MNP connection is attempted and if fails, a Normal mode
connection is established. (Default)
S37 DESIRED CONNECTION RATE
Range: 0-21 Unit: Decimal
Note:1. When the Nn comand is issued or the S37 register value is modified,
the +MS command subparameters are updated to reflect the speed and modulation specified by the S37 value (see +MS command). For example:
If N0 command is active, S37=10 updates the +MS command subparameters to reflect +MS=10,0,300,12000
If N1 command is active, S37=10 updates the +MS command subparameters to reflect +MS=10,1,300,12000
2. S37 is not updated by the +MS command.
3. Use of the +MS command is recommended instead of the Nn and S37=x commands. Nn and S37=x commands are supported for compatibility with existing communication software.
4. If an invalid number is entered, the number is accepted into the register, but S37 will react as though the default value has been entered.
S37=0 Attempt auto mode connection (DEFAULT) S37=1-3 Attempt to connect at 300bps S37=4 Reserved S37=5 Attempt to connect at 1200bps S37=6 Attempt to connect at 2400bps S37=7 Attempt to connect at V.23 (Not supported by Zoltrix V.34) S37=8 Attempt to connect at 4800bps S37=9 Attempt to connect at 9600bps S37=10 Attempt to connect at 12Kbps S37=11 Attempt to connect at 14.4Kbps S37=12 Attempt to connect at 7200bps
S38 DELAY BEFORE FORCED HANG UP
Range: 0-255 Unit: Seconds This register specifies the delay between the modems receipt of the H command to disconnect (or ON-to-OFF transition of DTR if the modem is set to follow the signal), and the disconnect operation. Applicable to error-correction connection only! This register can be used to ensure that data in the modem buffer is sent before the modem disconnects.
1. If S38 is set to a value between 0 and 254, the modem will wait that
number of seconds for the remote modem to acknowledge all data in the modem buffer before disconnecting. If time expires before all data is sent, the NO CARRIER result code will be issued to indicate that data has been lost. If all data is transmitted prior to time-out, the response to the H0 command will be OK.
2. If S38 is set to 255, the modem does not time-out and continues to
attempt to deliver data in the buffer until the connection is lost or the data is delivered.
S39 Bit Mapped Bit Mapped Registers. S40 Bit Mapped Bit Mapped Registers. S41 Bit Mapped Bit Mapped Registers.
S46 PROTOCOL SELECTION
Range: 136 or 138 Unit: Decimal This register controls V.42bis compression.
S46=136 Disable V.42bis compression. S46=138 Enable V.42bis compression.
S48 V.42 NEGOTIATION ACTION
Range: 0,7 or 128 Unit: Decimal The V.42 negotiation process determines the capabilities of the remote modem. However, when the capabilities of the remote modem are known and negotiation is unnecessary, this process can be bypassed.
S48=0 Disables negotiation; bypass the detection and negotiation phases;
and proceed with V.42 (LAPM).
S48=7 Enables negotiation. S48=128 Disables negotiation; bypass the detection and negotiation phases;
and proceed at once with the fallback action specified in S36. Can be used to force MNP.
S82 BREAK HANDLING OPTIONS
S82 is included for compatibility purposes only, changing this register will not have any affect.
S86 CONNECTION FAILURE CAUSE CODE
Range: 0,4,5,8,12,13,14 Unit: Decimal When the modem issues a NO CARRIER result code, a value is written to this S register to help determine the reason for the failed connection. S86 records the first event that contributes to a NO CARRIER message.
S86=0 Normal disconnect, no error occured. S86=4 Loss of carrier. S86=5 V.42 negotiation failed to detect an error-correcting modem at the
other end.
S86=9 The modems could not find a common protocol. S86=12 Normal disconnect initiated by the remote modem. S86=13 Remote modem does not respond after 10 re-transmissions of the
same message.
S86=14 Protocol violation.
S95 EXTENTED RESULT CODES
Range: The bits in this register can be set to override some of the Wn command options. A bit set to 1 in this register will enable the corresponding result code regardless of the Wn setting.
Bit Decimal Value Function 0 = 1 CONNECT CODE indicates DCE speed instead of DTE speed. 1 = 2 Append /ARQ (automatic repeat request) to verbose
CONNECT XXXX result code if protocol is other than none.
2 = 4 Enable CARRIER XXXX result code. 3 = 8 Enable PROTOCOL XXXX result code. 5 = 32 Enable COMPRESSION result code.
Note: To enable more than one function, add up the decimal values of the
function you want to enable.
Example:
To enable CARRIER, PROTOCOL, COMPRESSION; You would add 32+8+4. The command to enable these Functions would be ATS95=44
RESULT CODES
Verbal Numeric Value Value Description
OK 0 Modem successfully executed a command line.
CONNECT 1 Connection made at 300 bps.
RING 2 Modem detected an incoming call.
NO CARRIER 3 Modem lost or could not detect a remote
carrier signal within the Register S7 time.
ERROR 4 Modem found an error in the command line.
CONNECT 1200 5 Modem established a connection 1200 at 1200
1200bps.
NO DIALTONE 6 Modem did not detect a dial tone within 5
seconds after going off-hook.
BUSY 7 Modem detected a busy signal.
NO ANSWER 8 Five seconds of silence was not detected
when using the @ command in the dial command line.
CONNECT 0600 9 Modem established a connection at 600 bps.
CONNECT 2400 10 Modem established a connection at 2400 bps.
CONNECT 4800 11 Modem established a connection at 4800 bps.
CONNECT 9600 12 Connection made at 9600 bps.
CONNECT 7200 13 Connection made at 7200 bps.
CONNECT 12000 14 Connection made at 12000 bps.
CONNECT 14400 15 Connection made at 14400 bps.
CONNECT 16800 59 Connection made at 16800 bps.
CONNECT 19200 16 Connection made at 19200 bps.
(If modem is set to respond with connect message that indicates carrier rate, otherwise indicates software rate)
CONNECT 21600 61 Connection made at 21600 bps.
CONNECT 24000 62 Connection made at 24000 bps.
CONNECT 26400 63 Connection made at 26400 bps.
CONNECT 28800 64 Connection made at 28800 bps.
CONNECT 31200 Connection made at 31200 bps.
CONNECT 33600 Connection made at 33600 bps.
CONNECT 38400 17 Connection made at 38400 bps. (Indicates software rate)
CONNECT 57600 18 Connection made at 57600 bps. (Indicates software rate)
CONNECT 115200 19 Connection made at 115,200 bps.(Indicates software rate)
FAX 33 Fax detected. (Fax/Data answer mode)
DATA 35 Modem detected. (Fax/Data answer mode)
CARRIER 300 40 Carrier rate of 300 bps.
CARRIER 1200 46 Carrier rate of 1200 bps.
CARRIER 2400 47 Carrier rate of 2400 bps.
CARRIER 4800 48 Carrier rate of 4800 bps.
CARRIER 7200 49 Carrier rate of 7200 bps.
CARRIER 9600 50 Carrier rate of 9600 bps.
CARRIER 12000 51 Carrier rate of 12000 bps.
CARRIER 14400 52 Carrier rate of 14400 bps.
CARRIER 16800 53 Carrier rate of 16800 bps.
CARRIER 19200 54 Carrier rate of 19200 bps.
CARRIER 21600 55 Carrier rate of 21600 bps.
CARRIER 24000 56 Carrier rate of 24000 bps.
CARRIER 26400 57 Carrier rate of 26400 bps.
CARRIER 28800 58 Carrier rate of 28800 bps.
CARRIER 31200 Carrier rate of 31200 bps.
CARRIER 33600 Carrier rate of 33600 bps.
Note: The CARRIER Result Code must be enabled with S95 bit 2 or W1 commands.
COMPRESSION: 66 The modem has connected in MNP CLASS 5 class 5 and COMPRESSION message
reporting has been enabled.
COMPRESSION 67 The modem has connected in V.42bis V.42bis and COMPRESSION message reporting has
been enabled.
COMPRESSION: 69 The modem has connected without data NONE compression and COMPRESSION message
reporting has been enabled.
Note: The COMPRESSION Result Code must be enabled with S95 bit 5.
PROTOCOL: 76 Modem has connected without any NONE form of error connection. (No MNP4 or V.42)
PROTOCOL: 77 Modem has connected in the V.42 LAPM LAPM mode of error correction.
PROTOCOL: 80 Modem has connected in the MNP 4 ALT mode of error correction.
The PROTOCOL Result Code must be enabled with S95 bit 3 or W1 commands.
Rockwell has also added a response appended to the CARRIER result code to indicate that a V.FC connection has been established. Remember that the Rockwell V.34 chipset also supports Rockwell's V.FC standard. There is NOT a numeric equivalent for the CARRIER result code with the appended /VFC.
Following is an example response when connecting to a V.FC modem: (S95=47)
CARRIER 21600/VFC
PROTOCOL: LAP-M
COMPRESSION: V.42BIS
CONNECT 21600/ARQ
Following is an example response when connecting to a V.34 modem: (S95=47)
CARRIER 21600
PROTOCOL: LAP-M
COMPRESSION: V.42BIS
CONNECT 21600/ARQ