YML358-3 AA
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| Getting Started | |
| Using this Guide | |
| What is a Modem? | |
| Using your Modem | |
| AT Command Language | |
| AT Commands | |
| Advanced Commands | |
| Copyright 1997 Avtek Data Communications YML358-3 AA |
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Thank you for purchasing an Avtek Modem. Before reading this guide it is recommended you follow the instructions in the Read Me First guide to get you up and started.
Don't forget to register your Avtek Avenger 336.
This user guide includes a general description of modem operation as well as the modem's indepth feature and command information.
Using this Guide
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This manual is based around HTML, the document layout format used for Internet World Wide Web (www) pages. To navigate through this user guide you can click on any area where your mouse pointer changes to a hand (as seen at left), usually graphics or areas of red text (hypertext). |
The HTML pages of this manual can be viewed and printed with any browser that supports tables (such as NetScape V2.0 or greater or Internet Explorer V2.0 or greater). Alternatively, a copy is available in text format (avenger.txt) on the Documentation and Drivers disk.
A modem is a device that allows computers (and other electronic devices) to communicate via phone lines. It converts digital signals generated by the computer into analog (audio) signals which can be transmitted over a telephone line. The modem also transforms incoming analog signals into their digital equivalents so that the computer can understand them. Specific techniques used to transform the signals are called modulation protocols. A modem typically supports more than one modulation protocol.
The word, MODEM is an acronym and stands for MOdulator/DEModulator.
The speed of a modem (without data compression) is determined by the modulation protocols. e.g. A V.34 modem is capable of speeds up to 33600bps.
Please read the Australian Communications Authority warning notice if you are using your modem in Australia or the Telecom New Zealand warning notice if you are using your modem in New Zealand.
The Modem will always be in one of the following three functional states.
Communicating directly with your modem.
Dialling a number or answering an incoming call.
Connected to a remote system with the modems providing a transparent link.
When you turn on your modem it performs a self-test
and waits in command mode. This mode allows communication between
your computer and your modem by using the AT command language.
The modem recognises these commands because they are prefixed
by the characters, AT or at. This is short for - attention, I
want to issue a command. Commands are sent from the keyboard to
the modem via the serial port using a communications package,
and instruct the modem to carry out certain tasks or maybe wait
for a ring signal.The modem will adjust to the following
speeds: 57,600,
38,400, 19,200, 9,600,
4,800, 2400 1200 and
300 bps in the following data word formats:-
· 7 data bits, odd or even parity, one stop bit.
· 7 data bits, no parity, two stop bits.
· 8 data bits, no parity, one stop bit.
The modem will also respond back to your computer screen, from each command, with messages such as OK or CONNECT.
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From here on, all commands to be typed into the computer will be shown as bold. All responses from the computer will be bold and italic.
Enter: AT <Enter>
Response: OK
This indicates that the modem is communicating with your computer. If nothing happens it could be due to one of the following reasons:-
· Improper serial port selection.
· Improper installation.
Assuming that you have successfully completed the above test, try dialling a phone number. To make the modem dial a number:
Enter: ATDTn.....n <Enter>
where n.....n is the required number (up to 45 digits). It may be necessary for those users that are connected via a PABX, with an access code for the Public Switched Telephone Network (PSTN), to type a comma (,) between the access code and the main number. This will make the modem pause for two seconds before continuing dialling. Eg: ATDT0,9418 7693
The normal tone dialling technique utilised is with the ATDTn....n command. If your phone line doesn't support tone dialing use P instead of the T as in the above example.
After pressing the <Enter> key, the modem will dial the number that was entered. If the telephone is connected in parallel to the modem, it is important not to remove the handset whilst the dialling and connection procedures are taking place or at any other time during the call as corruption of the data can occur.
To abort the dialling and connecting process, type in any character on the keyboard. The modem will stop and return to command mode.
When the modem is instructed to either call another computer, or to answer an incoming call the modem enters the connecting to call mode. During this time the modem will be sending and receiving signals along the telephone line. These signals ensure correct connection and synchronisation with the connecting computer.
When the connection is made, the modem may respond with:
CONNECT line speed Advises you that the connection has been made and at what speed. The remote computer will normally respond with a second message.
The following results can indicate a problem occurred during the dial sequence.
NO DIALTONE The modem was unable to detect dial tone and did not dial the requested number, therefore, it automatically disconnected the call. Check the phone line connection.
BUSY The number dialled was busy and a busy tone was detected, therefore, it automatically disconnected the call. Try the number again shortly.
NO CARRIER The call was terminated either by a character being sent to the modem during the dialling phase or the telephone connection was unsuccessful.
Assuming you are now successfully connected, you may interact with the remote system.
At this point you will have issued a command to dial a number. The modem will have dialled the number and connected to the remote modem. Your modem's operation is now transparent to you, and you are communicating directly with the remote system.
Once you enter Data mode it is maintained until:
The AT Command language is used to control the modem. In most cases there is no need to learn the commands, but a basic understanding of the modem's operation is helpful.
All command lines must begin with the ASCII letters
'AT' except for the A/ command, which is discussed later. The
letters 'AT' are sometimes referred to as an attention code. This
command indicates to the modem that one or more commands are to
follow. The 'AT' and all following alphabetic characters may be
in upper or lower case.
AT must be entered in the same case:
"AT" or "at", NOT "At" or "aT".
By examining the AT prefix, the modem
is able to determine the communications rate of the local DTE
as well as it's parity setting. The modem then adopts these settings.
Multiple commands may appear on a single line and may be separated
by space characters for improved readability. Example:-
ATH <Enter>
AT S0=2 E0 &C1 &D2 <Enter>
ATDT (02) 9418 7693<Enter>
The command line is always terminated by the ASCII
Carriage Return <Enter> (except for A/). Once entered, all
commands following the AT command line prefix are executed. The
value for the carriage return character is programmed by S-Register
3 (S3).
If you make a mistake while entering a command character after
the AT, you may use the BACKSPACE key to clear the mistake. The
value for the backspace character is programmed by S5. The AT
prefix is processed immediately as it is entered and therefore
cannot be erased once it is typed in. The entire command line
may be terminated at any time by issuing CTRL-X (pressing Control
and X at the same time). The command line will be discarded and
an OK result message will be issued.
An Initialisation string is a set of commands that configure a modem for operation with a particular system. This "system" can be a software package or any device that has a serial port, such as a cash register.
There is not a standard Initialisation string for a modem. The string depends on the system that the modem is being used with.
If your modem isn't listed in the communications package that you are using, and there isn't a driver for the package on the driver disk try choosing a Generic Rockwell, Hayes Accura, Hayes, Optima or Standard Modem. If the software package requires an initialisation string try using AT &F S95=0 W0 before contacting technical support. If you are dialling a low speed service (2400 or below) try using AT &F S95=0 W0 \N0.
If you are connecting your modem to a device that isn't running communications software then see the Custom Configuration page.
Modulation Protocols
Modulation Protocols define the speed/s
at which a modem operates at. The International Telecommunications
Union - Telecommunications (ITU-T) (Formerly the CCITT) is a UN
sponsored body responsible for standardisation of communications
protocols. They have established a number of international telecommunications
standards such as V.34, V.32bis, V.32, V.22bis, V.22 and V.21.
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V.34
The V.34 protocol is the standard for 33600
bps connections. This standard was initially ratified as 28800bps
but was updated to include 33600bps in 1996.
V.32bis
V.32bis is the standard for 14400 bps
modems. A V.32bis modem can also fall back to 12000
and then to 9600, 7200 and 4800
bps. Therefore V.32bis is downwardly compatible with V.32.
V.32
V.32 is the standard for 9600bps communications.
It also supports the fallback speed of 4800bps.
V.23
V.23 is the standard for 1200/75bps
communications. This protocol was developed with terminal operators
in mind. It had a download speed of 1200bps, but an upload speed
of only 75bps. The upload speed was considered adequate for typing.
V.22 and V.22bis are standard modulation protocols for 1200 and 2400bps modems receptively. They do not have fall back speeds, but they can adjust to the lower modulation speed for poor line conditions.
V.21
V.21 is the standard for 300bps communications.
It is very rarely used anymore.
Error Correction V.42 and MNP2-4
Error correction protocols ensure that data
is received without any errors. There are two standards for error
correction protocols - V.42 and MNP 2 - 4. V.42 is a standard
ratified by the ITU-T which uses LAP-M error correction. It also
incorporates the MNP 2 - 4 (Microcom Networking Protocol) error
correction, which was developed by Microcom many years ago and
has become over the years a defacto industry standard. LAP-M is
technically far superior to MNP error correction.
V.42 actually incorporates the two error control schemes. V.42 uses LAP-M (Link Access Procedure for Modems) as the primary scheme and within the same standard it includes MNP 2, 3 & 4 as alternate schemes.
Therefore, a V.42 modem will be able to establish an error-corrected connection with a modem that only supports MNP 2 - 4. (MNP will automatically switch to the highest common settings during the handshake with the remote modem.). A modem that uses a proprietary error correction protocol will not be able to establish an error corrected link with a V.42 modem unless it supports V.42 and the proprietary protocol at the connection time. For example, Hayes V-series Smartmodem 9600 supports an error control protocol called LAP-B.
Noise on the phone line can impede any standard modem from delivering error-free data. V.42 (and MNP 2-4) filters out the line noise and automatically retransmits any corrupted data. When two modems establish an error-corrected connection they are said to have a reliable link.
The filtering process used by V.42 and MNP 2-4 is similar to the error correction scheme used by file transfer protocols (such as Xmodem). The two modems use a sophisticated algorithm to ensure that the data received is what has been sent.
The benefit of Error correction protocols is that they provide error correction even when you are reading e-mail messages or chatting with other people online. In other words, an error correction protocol is "on" all the time during your online session. Also a modem running just an error correction protocol can achieve a better throughput due to the framing techniques used and the ability to increase or decease the packet sizes depending on line conditions. For example, a modem operating at 2400 bps and running MNP Class 4 service transmits data at approximately 2640 bps.
Your modem has error correction turned on as a factory default.
Data Compression Protocols V.42bis and MNP-5
Besides error correction protocols, all
current high-speed modems also support data compression protocols.
That means the sending modem will compress the data on-the-fly
and the receiving modem will decompress the data to its original
form.
A modem cannot support data compression without utilising an error correction protocol. There are two standards for data compression protocols, ITU V.42bis and MNP-5. An MNP-5 modem requires MNP 4 error correction protocol and a V.42bis modem requires V.42 error correction protocol.
Almost all high-speed modems that support ITU V.42bis also incorporate MNP-5. The maximum compression ratio that MNP-5 can achieve is 2:1. That is to say, a 9600 bps (bits per second) MNP-5 modem can transfer data up to a maximum of 19200 bps. The maximum compression ratio for a V.42bis modem is 4:1. In this case the maximum throughput would be 38,400 bps. Unfortunately this is not always the case as it does depend on the type of data being sent.
In general, compression decreases the file size by 50% which effectively achieves twice the transfer speed for a standard text file. So a 9600 bps modem can effectively transmit 19200 bps.
V.42bis and MNP-5 cannot compress a file which is already compressed by software. In the case of MNP-5, it will even try to compress a pre compressed file and actually expand it, thus slow down the file transfer! V.42bis is much smarter and it passes the file through without adding any overhead to the overall file size.
Where you send files with a lot of repeated characters, V.42bis actually builds a data dictionary of these repeated characters and can compress the data much quicker, therefore the greater repeatability means a higher cps (characters per second) throughput.
In the case of most PC files and BBS files, they are already in a pre-compressed format, usually with a .ZIP or .LZH extension. Macintosh files are typically in a .SIT (Stuffit) or .CPT (Compact Pro) format and Amiga files are usually in the .ZOO, .ARC or .LZH format.
GIF files are already in a pre-compressed file format.
Your modem has data compression turned on as a factory default.
Local Flow Control and Data Buffering
Normally you will want to send data from
your PC to the modem as quickly as possible. If the modem is idle
and waiting for the computer to send data, you are not getting
the maximum performance from the modem.
Your computer is able to send data faster than the modem can handle so this is where local flow control is used.
A high-speed modem typically supports two kinds of local flow control: hardware handshaking using Clear to Send and Request to Send (CTS/RTS) along with software handshaking (XON/XOFF). Hardware flow control is the preferred method.
Hardware flow control (or hardware handshaking) works by altering voltage levels on the RTS and CTS signal lines at the RS232 serial interface between the modem and the computer.
CTS is used by the sending modem. When the local modem is ready to receive data, it raises the CTS signal to the local computer and the computer starts transferring data. If the modem is unable to accept the data as fast as it is received from the computer, the modem will lower the CTS line to inform the computer that the modem buffer is almost full (A high-speed modem typically contains a small amount of RAM which is used to provide data buffers). The computer will then suspend data transfer. Once the local modem has emptied its buffer by transmitting data to the remote modem, it will raise CTS again.
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RTS is used by the receiving computer. When the computer cannot accept data at the rate at which the modem is passing data, it will lower the RTS line. The computer then raises RTS again when it is ready to resume receiving data from the modem.
Software flow control (or software handshaking) acts in much the same way as hardware flow control, but it is achieved by embedding control character in the data stream. XON and XOFF are the most commonly used control characters.
The use of XON and XOFF during data transfer can create problems when a binary file contains the Control-S (^S) or XOFF character as a legitimate part of the data. Do not use this method if ^S and ^Q are part of the transmitted data.
Even though we can have an error correction protocol, we still need file transfer protocols when two modems want to exchange files. This is because the modems only look after the error correction whilst on-line. The File Transfer Protocols look after filenames, paths and the recovery of a file transfer if the modem link is lost for some reason during a transfer.
Errors that occur during file transfer are automatically detected and corrected by file transfer protocols. If a block of data is received incorrectly, the receiving system sends a message to the sending system and requests the re-transmission. This process is automatic. In some cases the crash recovery of a protocol means that not all the file has to be resent, only the un-transmitted section of the file is resent. When errors occur during file transfer, the communication program shows an error in the file transfer status window.
Which File Transfer Protocol Should You Use?
In general, we recommend Zmodem. If Zmodem
is not supported by the system you are calling, use Ymodem-G.
(If you are connecting to a UNIX system in a university, you may
have to use Kermit or Xmodem to transfer files.)
Zmodem
This is generally the best protocol to use
if the electronic service you are calling supports it. Zmodem
is extremely efficient and it provides crash recovery.
Like Ymodem-G, Zmodem does not wait for positive acknowledgment after each block is sent, but rather sends blocks in rapid succession. If a Zmodem transfer is cancelled or interrupted for any reason, the transfer can be resurrected later and the previously transferred information need not be resent.
ASCII
This is designed to work with ASCII text
files only. Note that you do not have to use this protocol when
transferring text files. The ASCII protocol is useful for uploading
a text file when you are composing e-mail online.
Xmodem
Xmodem is one of the most widely used file
transfer protocols. The original Xmodem protocol uses 128-byte
packets and a simple "checksum" method of error detection.
A later enhancement, Xmodem-CRC, uses a more secure Cyclic Redundancy
Check (CRC) method for error detection. Xmodem protocol always
attempts to use CRC first. If the sender does not acknowledge
the requests for CRC, the receiver shifts to the checksum mode
and continues its request for transmission.
Xmodem-1K
Xmodem 1K is essentially Xmodem CRC with
1K (1024 byte) packets. On some systems and bulletin boards
it may also be referred to as Ymodem.
Y Modem
Ymodem is essentially Xmodem 1K that allows
multiple batch file transfer. On some systems it is listed as
Ymodem Batch.
Y Modem-G
Ymodem-G and Imodem should only be used
with modems that provide built-in error correction protocols.
These file transfer protocols do not provide any error-detection
or recovery capability. This improves the transfer speed. If a
problem occurs during the file transfer, the transfer session
will be aborted. A reliable link between two modems does not provide
absolute guarantee for the data integrity during file transfer.
Kermit
Kermit was developed at Columbia University.
It was designed to facilitate the exchange of data among very
different types of computers (mainly minicomputers and mainframes).
You probably will not need to use Kermit unless you are calling
a minicomputer or mainframe at an educational institution.
Sealink
Sealink is a variant of Xmodem. It was developed
to overcome the transmission delays caused by satellite relays
or packet-switching networks.
| Command Line Syntax |
| Standard Commands |
| & Commands |
| \ Commands |
| % Commands |
| +MS Command |
| MNP10 Commands |
| Escape Codes |
| Distinctive Ring |
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Advanced
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| A/: | Repeat Command |
| A: | Answer Call |
| B: | ITU-T Or Bell mode |
| C: | Carrier Control |
| D: | Dial |
| E: | Echo Commads |
| F: | Speed Selection |
| H: | On/Off Hook |
| I: | Identification request |
| L: | Speaker Volume |
| M: | Speaker Control |
| N: | Automode |
| O: | Return Online |
| P: | Set Pulse dial |
| Q: | Result code display |
| S: | Read/Write S Register |
| T: | Set Tone dial |
| V: | Verbal Result Codes |
| W: | Negotiation Progress Reporting |
| X: | Dial/busy tone detection |
| Y: | Long Space disconnect |
| Z: | Reset Modem |
The modem command interpreter loads the command line into a memory buffer which has the capacity to hold up to 45 characters. The AT, carriage return and line feed control characters are not placed in the buffer. Because commands remain in the buffer until a new set overwrites them, the A/ command can be utilised to repeat these previous commands.
The A/ command is the only command that is not
preceded by the AT command line prefix. The A/ command takes effect
immediately and does not require a carriage return.
This command should be the last one on the command line. No further commands from the command line will be processed after this command is executed. Use it to answer a call immediately. It causes the Modem to go 'off-hook' in Answer mode. It then issues an answer sequence regardless of the contents of S-Register 0.
After handshaking (exchange of carrier signals) with the remote modem it will proceed to the online state. If no carrier is detected within the time specified in S7 (default 50 seconds) the modem will terminate the call and go on-hook. Any character entered via the DTE during this sequence will cause the command to terminate.
Parameters: n=0,1 Default: 0
Selects the type of handshake the modem will use during answer or fixed speed connections with the remote modem. This must be set to be the same as the remote modem. Australia, New Zealand and European countries use ITU recommendations, the USA uses Bell.
B0 ITU V.22bis, V.23, V.22, V.21.
B1 Bell 103, 212A, 2400.
Parameters: n=0,1 Default: 1
Controls the transmitted carrier signal. The modem is set to turn the carrier on and off as required for communications. This command is included for compatibility with Hayes 300 modems only. C0 is not a valid option.
C0 Error
C1 Returns OK - Takes no action.
The Modem dials a number and attempts a connection to a remote modem. The command also causes the modem to execute any number of dial modification commands that can be entered in the form of the dial command string.
The Dial command takes the form ATDn,
where n is a string of dial digits and modifiers. The length of
the dial string is limited by the size of the command buffer.
The command buffer is capable of storing a maximum of 45 characters.
The dial digits and modifiers include the characters 0
to 9, A B C D # and * and the dial modifiers:
T , ; P R ! @ W and S=n.
Command Description
T Selects that the numbers following will be touch tone dialled (DTMF).
P Selects that the numbers following will be pulse dialled.
0..9 The dial digits.
ABCD#* These are tone dial digits only.
, Will cause the modem to delay before dialling the next number. This feature may be utilised while using a PABX system where a delay is required before proceeding with dialling. (See S8 for delay period)
; This will place the modem back into command state after dialling. The modem will not attempt to connect to the called party. This may be used for automatic dialling of phone numbers. For example, ATDT5348192; will touch tone dial the number 5348192 and then return to command state. If an optional handset is attached and is off-hook the caller is now connected to the called party.
J Perform MNP 10 link negotiation at 1200bps.
K Enable power level adjustment during MNP10EC link negotiation.
L Last number re-dial. The L must immediately follow the D.
R An accepted code, but not acted on.
W Wait for dial tone (up to S7 seconds) before processing the next symbol in the dial string. If the modem does not detect dial tone in the specified time it will go on-hook and issue the NO DIALTONE result code.
@ Wait for quiet answer. The modem will listen for a period of 5 seconds of silence. If the 5 seconds of silence are not detected before the S7 time expires, the modem will go on-hook and issue the result NO ANSWER.
S=n Dial a number stored in the dial directory. The currently selected entry will be dialled unless the optional parameter 'n' is supplied. In this case, entry 'n' in the dial directory will be dialled.
! Hook Flash, put modem on hook for half a second. This is used with some PABX systems to get another line or to do some auxiliary function.
& Wait for AT&T "bong" tone before continuing with dial string.
If the ATD command is entered without parameters, the modem will go off-hook and wait for carrier for the period given in S7. The ATD command will be aborted at any time a character is sent to the modem while it is dialling or interpreting tones or carrier.
Parameters: n=0,1 Default: 1
Controls whether characters sent to the modem are echoed back to the DTE.
E0 Do not echo commands as they are entered by the user.
E1 Echo commands as they are entered.
Parameters: n = 0..10 Default: 0
If you have a 33600 bps or faster modem please see
the +MS command
This command selects the line modulation (speed) for 14400 bps
modems. This command interacts with S37
and the ATN command.
F0 Auto
mode detection, line speeds from 14,400 (V.32bis)
to 300bps (V.21).
F1 Force
V.21 / Bell 103 (according to setting of ATB command) at
300bps.
F2 Ignored.
OK response returned.
F3 Force
V.23 75TX/1200RX originate or 1200TX/75RX
answer FSK.
F4 Force
V.22/Bell 212A (according to setting of ATB command) at 1200
bps.
F5 Force
V.22bis/Bell 2400 (according to setting of ATB command).
F6 Force
V.32 4800bps.
F7 Force
V.32 7200bps.
F8 Force
V.32 9600 bps.
F9 Force
V.32bis 12000 bps.
F10
Force V.32bis 14400 bps.
Note that the modem does not have a command
to force a fixed speed between PC and modem (DTE rate).
Parameters: n=0,1 Default: 0
Forces the modem on or off hook. This can be used to test the presence of dial tone before dialling (ATH1) or Hangup the modem at the end of a call.
H0 Will put the modem On-Hook or hang the line up.
H1 Will take the modem Off-Hook, can be used to busy out the line.
Parameters: n=0..3 Default: 0
Interrogates the modem for its product identification code, ROM Checksum or ROM checksum status and reports this information to the DTE.
I0 Reports the product code.
I1 Reports the checksum.
I2 Computes the ROM checksum and compares it with the stored value.
I3 Requests the modem to identify itself and its revision.
I4 Reports model type.
Parameters: n=0..3 Default: 1
Sets the volume of the speaker inside the modem. The speaker is also controlled by the ATMn commands.
L0,1 Low Volume.
L2 Medium Volume.
L3 High Volume.
Parameters: n=0..3 Default: 1
Controls when the speaker is turned on or off. The volume of the internal speaker is adjusted by the ATLn commands.
M0 Speaker is off always.
M1 Tells the Modem to turn the speaker on during dialling, but turn off when carrier has been received from a remote modem.
M2 The speaker is on always.
M3 Keep the speaker on until a carrier is detected but off during dialling.
Nn - Automode Enable
Parameters: n = 0,1 Default: 1
Sets Automode detection. This command allows the modem to autodetect the handshake of the other modem. If turned off, the modem will only handshake at the speed set by S37.
N0 Turns off automode detection. A subsequent handshake will be conducted according to the contents of S37 and if S37 is zero, according to the most recently sensed DTE speed.
N1 Turns on automode detection. This command is equivalent to ATF0.
Parameters: n=0,1 Default: None
Returns the modem to online state, thereby re-establishing a connection that has already been made. If not currently connected to a remote modem, an ERROR will be returned by the modem.
O0 Will return the modem to data mode (On-Line).
O1 Will issue a retrain sequence to the remote modem and then go online.
Sets the Modem to pulse dial mode. The command may be entered following the AT command prefix or within the dial string. Once set, all following dial commands will pulse dial.
Parameters: n=0,1 Default: 0
Allows the modem to send result codes the DTE. The codes are the responses to commands issued or connections made to other modems. The type of response code is controlled by the ATVn commands.
Q0 Enables result codes to be sent to the DTE.
Q1 Quiet mode. The modem will not send any result codes.
Sn? - Read S Register
Parameters: n=0..95 Default: None
Sn? command will read the contents of S register n. The function of each S register is described on your screen.
Parameters: n=0..95, x=0..255 Default: None
Sn=x command assigns a value to the selected S-Register. Please see details about each register before changing values. Unpredictable results can be expected if some S-Registers are assigned incorrect values.
Sets the Modem to tone dial telephone numbers. This command may be set following the AT command line prefix or from within the dial string. Once set, all following dialling will be tone dialling.
Parameters: n = 0,1 Default: 1
Sets the type of result codes being sent to the DTE by the modem. The modem can send either English (verbal) or numerical (digit) results for operations carried out by the modem.
V0 Selects digit result codes.
V1 Selects words. Word strings are preceded and terminated with both a carriage return and a line feed character.
Wn - Negotiation Progress Reporting
Parameters: n = 0..2 Default: 0
Enables the modem to send out an additional set of result codes. The result codes report on the carrier speed (300, 1200, 2400, 4800, 9600, 12000, 14400, 16800, 19200, 21600, 24000, 26400, 28800, 31200, 33600) the link level protocol (MNP2,3,4,5, V.42, V.42bis) and operating port speed (300, 1200, 2400, 4800, 9600, etc.).
W0 On connection DTE speed is reported (eg. CONNECT 57600) Note: This also requires that S register 95 must be set to its default (Eg ATS95=0)
W1 On connection carrier speed, protocol, compression and DTE port speed reported. In Direct mode only carrier and DTE speeds are reported.
W2 On connection Line speed is reported (eg. CONNECT 9600) Note: This also requires that S register 95 must be set to its default (Eg ATS95=0)
Xn - Extended Result Codes and Call Progress
Parameters: n = 0..4 Default: 4
Determines whether the modem responds to dial tone and busy signals. It also selects how the connect message result code will be sent. When the modem ignores the dialtone it blind dials. This means that it will wait the time specified in S6 (default 4 seconds) and then dial the requested number, regardless of the presence of dialtone. The modem looks for dialtone for up to 5 seconds. If not found a NO DIALTONE result code will be issued.
X0 Ignore dialtone and busy detect. Send CONNECT message when connection is established.
X1 Ignore dialtone and busy detect. Send CONNECT speed message when connection is established.
X2 Ignore busy detect, look for dialtone before dialling and send CONNECT speed message when connection is established.
X3 Ignore dialtone detect, look for busy signals and send CONNECT speed message when connection is established.
X4 Look for dial and busy tone signals and send CONNECT speed message when connection is established.
Parameters: n=0,1 Default: 0
Sets the modem to act on a long space being sent by the remote modem. When enabled the modem will hangup upon receiving a long space.
Y0 Disable long space disconnect.
Y1 Enable long space disconnect.
Parameters: n=0,1 Default: 0
This command performs a software reset of the modem and fetches one of the configuration profiles (stored with the &Wn command) from non-volatile memory and loads it into the active configuration. Any following commands in the command line will not be executed. Example:
Z0 Reset and load profile 0
Z1 Reset and load profile 1
| &C: | Carrier Mode |
| &D: | DTR Control |
| &F: | Factory Defaults |
| &G: | Gaurd Tones |
| &J: | Phone Jack Type |
| &K: | Flow Control |
| &L: | Line Type |
| &M: | Comms Mode |
| &P: | Pulse Ratio |
| &Q: | Comms Mode |
| &R: | RTS/CTS Options |
| &S: | DSR Options |
| &T: | Test Modes |
| &V: | View Profiles |
| &W: | Store Profile |
| &Y: | Default User Profile |
| &Z: | Store a phone number |
Parameters: n=0,1 Default: 1
Controls the operation of the Data Carrier Detect (DCD) signal line from the modem to the DTE, which if set, indicates the state of the carrier signal between the two modems.
&C0 The modem keeps the DCD signal in the ON condition disregarding the state of the data carrier from the remote modem.
&C1 The DCD will track the state of data carrier from the remote station.
Parameters: n=0..3 Default: 2
Tells the modem how to react to an ON to OFF transition of the Data Terminal Ready (DTR) signal from the DTE. The action of DTR is dependant upon the current &Q setting.
&D0 with &Q set to:
&Q0, &Q5, &Q6
DTR drop is ignored (Assumed ON) by the modem & it takes no
action.
&Q1, &Q4
DTR drop causes the modem to hang up with Auto Answer not affected.
&Q2, &Q3
DTR drop causes the modem to hang up with Auto Answer inhibited.
&D1 with &Q set to:
&Q0, &Q1 ,&Q4, &Q5, &Q6
DTR drop forces the modem back into local command state. Other
commands can then be issued to the modem.
&Q2, &Q3
DTR drop causes the modem to hang up with Auto Answer inhibited.
&D2 with &Q set to:
&Q0 through &Q6
DTR drop causes the modem to hang up. Auto answer is inhibited.
&D3 with &Q set to:
&Q0, &Q1, &Q4, &Q5, &Q6
DTR drop causes the modem to hang up and the modem is initialised
as if an ATZ command was issued.
&Q2, &Q3
DTR drop causes the modem to hang up with Auto Answer inhibited.
&F - Reset to Factory Settings
A factory configuration profile containing default settings for all configuration S registers is permanently stored in the modem's EPROM. You may restore the modem's active configuration to the factory settings by issuing this command.
Parameters: n=0..2 Default: 0
Selects the use of guard tones. These are transmitted while the modem is in the online state, and are not used in Australia.
&G0 Disable guard tone generation.
&G1 Reserved.
&G2 1800Hz guard tone may be selected by issuing this command.
Parameters: n=0,1 Default: 0
Sets jack type. Provided for compatibility with Hayes modems only.
Parameters: n = 0..6 Default: 3
When operating at port speeds higher than line speeds the modem's internal buffer may fill up. When the buffer is nearly full the modem will instruct the DTE to stop transmitting data to it using XOFF or dropping CTS. As the buffer reaches a near empty state the DTE is instructed to start sending to the modem again using XON or asserting CTS, or the DTE can instruct the modem to stop sending data using XOFF or dropping RTS. To restart transmission from the modem the DTE may assert RTS or send an XON, depending on the mode set.
&K0 Local flow control off.
&K1,2 Not used
&K3 Sets local flow control to RTS/CTS.
&K4 Sets local flow control to XON/XOFF.
&K5 Sets flow control to transparent XON/XOFF.
&K6 Sets local flow control to both RTS/CTS and XON/XOFF
Parameters: n=0,1 Default: 0
Selects operation for either leased or dial-up line.
&L0 Selects dial-up communication.
&L1 Reserved, the modem will return an OK response.
Parameters: n=0..3 Default: 0
This command selects the communication mode.
&M0 Asynchronous mode. The modem will connect in the asynchronous mode and remain in the asynchronous on-line state when a connection is established.
&M1 Reserved.
&M2 Reserved.
&M3 Reserved.
Parameters: n=0..3 Default: 1
Controls the ratio of the 'off-hook' to 'on-hook' interval used for pulse dialling.
&P0 Selects Make-Break ratio of 39%-61% respectively (U.S.A.)@10 pps.
&P1 Selects Make-Break ratio of 33%-67% respectively (Aust) @ 10 pps.
&P2 Selects Make-Break ratio of 39%-61% respectively @ 20 pps.
&P3 Selects Make-Break ratio of 33%-67% respectively @ 20 pps.
This command selects the type of asynchronous communication mode used.
&Q0 Asynchronous direct mode. The modem will connect in the asynchronous mode and remain in the asynchronous on-line state when a connection is established. Flow control is not available when this command is selected.
&Q1 Reserved.
&Q2 Reserved.
&Q3 Reserved.
&Q5 Error-corrected mode. The modem will establish an error-corrected connection based upon the \N setting.
&Q6 Selects asynchronous buffered mode. The modem will connect in asynchronous mode and remain in asynchronous on-line state when a connection is established.
Parameters: n = 0,1 Default: 1
This command controls the operation of the CTS signal. Its operation is modified if hardware flow control is selected (See &K command).
&R0 CTS tracks the state of RTS, but is delayed by the value of S26.
&R1 CTS is always ON and transitions on the RTS signal line are ignored.
Parameters: n = 0,1 Default: 0
Sets the operation of the Data Set Ready (DSR) interface signal from the modem to the DTE.
&S0 DSR always active.
&S1 DSR on at the start of handshaking and off when in test mode.
Parameters: n = 0..8 Default: 5
Selects the self test modes.
Note: The modem MUST be in a non-buffered mode for correct operation Eg: AT\N0.......
&T0
Terminate current tests.
&T1
Run Local Analog Loopback test.
&T3
Runs Local Digital Loopback test.
&T4
Enables Remote Digital Loopback test.
&T5
Disables Remote Digital Loopback test.
&T6 Requests
Remote Digital Loopback test.
&T7
Requests Remote Digital Loopback test with Self Test option.
&T8
Local Analog Loop test with Self Test option.
&V - View Active Configuration/Profiles
Display the active and stored configuration profiles
along with stored telephone numbers.
&V0
Displays main AT command and S register values for active and
stored profiles.
&V1
Displays current or previous call information
Parameters: n=0,1 Default: 0
Writes the active configuration profile to non-volatile memory. Once you have altered the settings of the S-registers in the active configuration to suit a specific application, save them with the (&Wn) command.
&W0 Save as user profile0.
&W1 Save as user profile 1.
Parameters: n = 0..1 Default: 0
Loads stored configuration 'n' at modem power up. Also refer to &W0.
&Y0 Selects stored profile 0 on power up or reset
&Y1 Selects stored profile 1 on power up or reset
Parameters: n = 0..3, x=dial string Default: 0
Allows up to 4 dialling strings to be stored into Non volatile memory which can be recalled using the ATDSn dial string. The telephone number, including dial modifiers, has a maximum length of 45 characters. A carriage return executes this command and the fields are stored in the non-volatile memory.
Format: AT&Zn=<Number>
eg: Enter: AT&Z0=T0,418 7693<Enter>
Response: OK
| \A: | Max. MNP Block Size |
| \B: | Transmit Break |
| \G: | Modem to Modem Flow Control |
| \K: | Break Control |
| \L: | Block MNP link |
| \N: | Operating Mode |
Parameters: n = 0..3 Default: 3
The size of the MNP protocol block can be changed to suit a particular application. Both modems must have the same block size.
\A0 Sets block size maximum 64 bytes.
\A1 Sets block size maximum 128 bytes.
\A2 Sets block size maximum 192 bytes.
\A3 Sets block size maximum 256 bytes.
Parameters: n = 1..9 Default: 3
When this command is entered during a non-MNP connection, the modem sends a break signal to the remote modem. The length of the break is in multiples of 100 msec
(If n=0, the default value 3 is used; if n is greater than 9, 9 is used.)
\Gn Modem to Modem Flow Control
Parameters: n = 0,1 Default: 0
Enables or disables modem to modem flow control during a Normal mode connection. Since the reliable link (error correction) has its own method of flow control, the \Gn command is ignored when error correction is selected. However, the DTE to modem flow control (&Kn) remains active during a reliable link.
\G0 Disables flow control (XON/XOFF).
\G1 Enables flow control (XON/XOFF).
Parameters: n = 0..5 Default: 5
Determines the modem response when a BREAK is received from the DTE or the remote modem. During MNP mode, the remote modem's BREAK control setting determines the local modem response to handle the BREAK.
When a BREAK is received from the DTE during Normal or MNP/V.42 mode:
\K0,2,4 Modem enters the command mode (waiting for AT) without sending a BREAK to remote modem.
\K1 Modem clears the terminal and modem buffers and sends a BREAK to remote modem.
\K3 Modem does not clear the buffers but sends a BREAK to remote modem.
\K5 Modem sends a BREAK to the remote modem in sequence with any transmitted data.
When a BREAK is received from the remote modem during Normal mode:
\K0,1 Modem clears terminal and modem buffers and sends a BREAK to local DTE.
\K2,3 Modem does not clear buffers but sends a BREAK to local DTE.
\K4,5 Modem sends a BREAK in sequence with any data being buffered.
When a BREAK is received from the DTE during Direct mode:
\K0,2,4 Modem sends a BREAK to remote modem and enters command mode (waiting for AT).
\K1,3,5 Modem sends a BREAK to remote modem.
Parameters: n = 0,1 Default: 0
Selects between Block and Stream modes of MNP operation
\L0 Initiates a stream link. With this type of link the data is transferred in packets up to the size defined by the \A command.
\L1 Initiates a block link. With this type of link the data is sent in packets of a fixed size of 256 bytes. This command will force an MNP Class 4 link attempt, and is used primarily for special file transfer software. This parameter must be set before a link is attempted, it cannot be changed for a link which is in progress.
Parameters: n = 0..5 Default: 3
Controls error correcting mode to be negotiated in subsequent connection.
\N0 Normal mode. Disable error correction. Speed buffering ON (forces AT&Q6).
\N1 Direct mode (forces AT&Q0). DTE/DCE speeds must be equal.
\N2 Enable V.42 (LAP-M or MNP4) error correction. Failure to connect in reliable mode will result in the modem hanging up. Forces AT&Q5 - S36=4, S48=7.
\N3 Enable Auto-reliable mode. V.42 (LAP-M or MNP4) error corrected links preferred, non-error corrected links as fallback. Forces AT&Q5, S36=7, S48=7 (default).
\N4 Enable V.42 LAP-M error correction only. Forces AT&Q5, S48=0.
\N5 Enable MNP4 error correction only. Forces &Q5, S36=4, S48=128.
| %C: | Compression Control |
| %E: | Auto Retrain enable |
| %L: | Report received signal level |
| %Q: | Eye Quality Monitor (EQM) |
Parameters: n = 0..3 Default: 3
Determines whether the modem attempts to use data compression during reliable and auto reliable connections. Both modems must have the compression control command at its default setting (AT%C1) and have the Block MNP Link command at its default setting (AT\L0) at the time the reliable link is made, otherwise the link will be established without the compression facility.
%C0 Disable data compression during reliable and auto reliable connections.
%C1 Enable MNP Class 5 compression, disable V.42bis compression.
%C2 Enable V.42bis compression data, disable MNP Class 5 compression.
%C3 Enable both
V.42bis compression and MNP Class 5 data compression.
Parameters: n = 0,1 Default: 2
The auto retrain enables the modem to generate a retrain sequence to the remote modem when a sustained poor quality line is detected or if the line quality improves, the Modem will retrain and fall forward.
%E0 Disables Line quality monitor and auto retrain.
%E1 Enables Line quality monitor and auto retrain.
%E2 Enables Line quality monitor and fallback/fallforward
%E3 Enables Line quality monitor and auto retrain, but hangs up when EQM reaches threshold.
%L - Report Received Signal Level
Returns a value identifying the received signal level.
(For example 010 will be reported if the received level is -10dBm)
%Q - Eye Quality Monitor (EQM)
Returns the Eye Quality Monitor (EQM) value. Based on the EQM level a retrain with fall back or fall forward may be initiated depending on the %En command setting.
This extended-format command selects the speed (modulation)
and, optionally;
The command format is:
+MS=<mod> [,[<automode>]
[,[<min_rate>] [,[<max_rate>]
]]]
Notes:
1. Subparameters not entered (enter a comma only or <CR>
to skip the last subparameter) remain at their current values.
See also, Sub-parameter Definitions, Reporting Selected Options,
Reporting Supported Options
Notes:
1. Sub-parameters not entered (enter a comma only or <CR>
to skip the last sub-parameter) remain at their current values.
The modem can send a string of information to the
DTE consisting of selected options using the following command:
+MS?
The response is:
+MS:
<mod>,<automode>,<min_rate>,<max_rate>
For example,
+MS: 11,1,300,33600,0,0
[33600 default values]
See Sub-parameter
definitions
The modem can send a string of information to the
DTE consisting of supported options using the following command:
+MS=?
The response is:
+MS: (list of supported <mod> values), (list of supported
<automode> values),(list of supported <min_rate> values),
(list of supported <max_rate> values)
For example,
+MS:
(0,1,2,3,9,10,11,64,69),(0,1),(300-33600),(300-33600)
1. <mod>
= A decimal number which specifies the preferred modulation (automode
enabled) or the modulation (automode disabled) to use in originating
or answering a connection. The options are:
| <mod> | Modulation | Possible Rates (bps) |
| 0 | V.21 | 300 |
| 1 | V.22 | 1200 |
| 2 | V.22 bis | 2400 or 1200 |
| 3 | V23 | 1200 / 75 |
| 9 | V32 | 9600 or 4800 |
| 10 | V32 bis | 14400, 12000,
9600,
7200, or 4800 |
| 11 | 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 |
2. <automode>
is an optional numeric value which enables or disables automatic
modulation negotiation using V.8 bis/V.8 or V.32 bis Annex A.
The options are:
<automode> Option Selected Notes
0 Automode disabled
1 Automode enabled using
V.8 bis/V.8 or V.32 Annex A Default
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=10,0,1200,4800 selects
V.32 bis 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=10,0,2400,14400
selects V.32 bis 14400, 12000,
9600, 7200, 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=10,0,12000,12000
selects V.32 bis 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 bis/V.8, or V.32 bis Annex A if V.8 bis/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.32 bis 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.32 bis 12000 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 connection. The value is decimal coded,
in units of bps, e.g., 28800 specifies the highest
rate to be 28800 bps. The default is 33600 for 33600
bps modems.
Traditionally MNP10 has been used to allow connection between two Modems across a cellular link. It will maintain a link connection no matter what the line quality. This will avoid repeated attempts to log on or to transfer files. If the signal to noise ratio decreases, the Modem can be forced to retrain so that a slower carrier can be adopted, ensuring the link is maintained.
)Mn - Automatic Power Level AdjustmentParameters: n = 0,1 Default = 0
Enables or disables automatic power level adjustment during an MNP10 link negotiation.
)M0 Disable power level adjustment. Allow transmitter adjustment if cellular operation is requested.
)M1 Enables power level adjustment during MNP10 link negotiation. )M1 should not be used with *H2
*Hn - Link Negotiation SpeedParameters: n = 0,1,2 Default = 0
Controls the connection speed for link negotiations before up-shift occurs between two MNP10 modems. The parameter value is written to S28 bits 6 & 7.
*H0 Link negotiation occurs at the highest supported speed
*H1 Link negotiation occurs at 1200 bps (cellular connections)
*H2 Link negotiation occurs at 4800 bps (used on poor phone lines)
-Kn - MNP Extended Services
Parameters: n = 0,1,2 Default = 1
Enable/disables conversion of a V.42 LAPM connection to an MNP10 connection.
The parameter value, if valid is written to S40, bits 0 and 1.
-K0 Disables V.42 LAPM to MNP10 conversion.
-K1 Enables V.42 LAPM to MNP10 conversion.
-K2 Enables V.42 LAPM to MNP10 conversion, inhibits MNP Extended Services initiation during V.42 LAPM answer mode detection phase.
-Qn - Fallback to V.22bis/V.22
Parameters: n = 0,1 Default = 1
Enables or disables fallback from MNP10 to V.22bis/V.22. The parameter if valid is written to S40 bit 1.
-Q0 Disable fallback to 2400 bps and 1200 bps
-Q1 Enable fallback to 2400 bps and 1200 bps
-SEC=n,x - MNP10EC Control
Parameters: n = 0,1, x=10-30 Default = 10
MNP10EC (MNP10 Enhanced Cellular) is a superior enhancement to the MNP10 cellular protocol. By default, MNP10EC is disabled and can be enabled by entering the AT-SEC=1 command.To default value for the transmit power in -dBm is 10 and is suitable for the majority of connections. The range for this value can be adjusted between 10 to 30 -dBm.
-SEC=0 Disable MNP10EC
-SEC=1,n Enable MNP10-EC
@Mn - Initial Cellular Power Level Setting
Parameters: n = 0 - 31 Default = 0
Sets the initial transmit power level for up-shift at connect until line conditions can be determined.
@M0 -26 dBm
@M1 -30 dBm
@M2 -10 dBm
@M3 to @M10 - 10dBm
@M11 -11 dBm
@M12 -12dBm
to
@M31 -31dBm
:En - Compromise Equaliser Enable
Parameters: n = 0,1 Default = 1
Enables or disables the V.32 compromise equaliser. The parameter value is written to S201 bit 5. This can be used if connected to flat line or cellular connection.
:E0 Disable equaliser
:E1 Enables the equaliser
When a connection has been established between the host modem and a remote station, the host modem will assume the online state. The escape code sequence permits the modem to return to the command state without hanging up.
The escape code consists of a string of 3 ASCII '+' characters. (The '+' is the default. You may change its value by altering S2.) To return to the command state from the online state:-
(1) Do not transmit any characters to the modem for a guard time equal to the value given by S12 (usually 2 seconds).
(2) Quickly type the string '+++' but do not enter a carriage return.
(3) Repeat step (1).
If these steps are followed correctly the modem will respond with the OK result code.
The purpose of the guard time interval is to prevent the modem from interpreting 3 consecutive '+' characters within the user's data as an escape code. The escape code characters may be reprogrammed to any 8 bit value by writing to S2.
Distinctive Ring allows the modem to be set to recognise
different ring signals from Telstra. Telstra can currently provide
3 different styles of ring - standard, FaxStream Duet and Easycall
Multiple Number.
-SDR=n Distinctive Ring
Parameters: n=0,2,4,7 Default: 0
-SDR=0 - the modem will report RING when it detects any
ring signal.
-SDR=2 - the modem will report RING2 when it detects standard
ring. It will ignore any other ring signal
-SDR=4 - the modem will report RING3 when it detects Faxstream
Duet or Easy Call Multiple Number ring. All other ring signals
will be ignored.
-SDR=7 - the modem will report all ring signals with RINGx, where
x indicates the ring style.
| Custom Configuration |
| AT Commands |
| S Registers |
| Connect messages |
| Cable configuration |
When configuring a modem there are a number of critical settings. Most of these settings are dependant upon the system that you are connecting the modem to.
Does the system :
Does the remote modem :
Saving the settings (&W)
e.g. When connecting the modem to a system for dial in access that
requires an intialisation string of
AT &F S0=2 &K4 &D2 E0 Q1 &W to be sent to the
modem at 19200 port speed.
| Register | Description |
| S0 | Rings to answer on |
| S1 | Ring Count |
| S2 | Escape Code character |
| S3 | Carriage Return character |
| S4 | Line Feed Character |
| S5 | Back Space Character |
| S6 | Wait time for dial tone |
| S7 | Wait time for carrier |
| S8 | Pause time for dial delay |
| S9 | DCD response time |
| S10 | Lost carrier time to hang up |
| S11 | DTMF tone duration |
| S12 | Escape code guard time |
| S14 | Bit Mapped |
| S16 | Modem test option |
| S18 | Test timer |
| S21 | Bit Mapped |
| S22 | Bit Mapped |
| S23 | Bit Mapped |
| S24 | Sleep inactivity timer |
| S25 | Delay to DTR |
| S26 | RTS-CTS delay interval |
| S28 | Bit Mapped |
| S29 | Flash dial modifier timer |
| S30 | Bit Mapped |
| S31 | Bit Mapped |
| S32 | XON character |
| S33 | XOFF character |
| S36 | LAP M Failure control |
| S37 | Line Connection speed |
| S38 | Delay before forced hangup |
| S39 | Flow Control |
| S40 | Bit Mapped |
| S41 | Bit Mapped |
| S46 | Data Compression Control |
| S48 | V.42 Negotiation Control |
| S82 | LAP M Break Control |
| S91 | Data Transmit Level |
| S92 | Fax Transmit Level |
| S95 | Result Code Message Control |
S0 - Number of Rings until Auto Answer
Selects when the modem will auto answer the telephone. A value of 0 will inhibit the modem from answering the telephone, instead, the modem will only indicate that the telephone is ringing. Please note that this setting is also dependent on the &Dn (DTR) setting.
| Default: | 0 |
| Range: | 0..255 |
| Units: | rings |
E.G. To set the modem to answer on the second ring type AT S0=2 in a terminal package. Please note that many communications packages send the ATA command to the modem to answer incoming calls. In these cases make sure that S0=0, the default setting.
Stores a count of how many times the telephone has rung. The ring count will be reset if a ring is not received for 8 seconds.
| Default: | 0 |
| Range: | 0..255 |
| Units: | rings |
Stores the ASCII value of the character used as the escape code (43 is the '+' character). The escape code is used to switch from the online state to the command state.
| Default: | 43 |
| Range: | 0..127 |
| Units: | ASCII |
S3 - Carriage Return Character
Stores the ASCII value of the character used for a carriage return.
| Default: | 13 |
| Range: | 0..127 |
| Units: | ASCII |
Stores the ASCII value of the character used for a line feed.
| Default: | 10 |
| Range: | 0..127 |
| Units: | ASCII |
Contains the ASCII value of the character used to erase a character in the command line.
| Default: | 8 |
| Range: | 0..32 |
| Units: | ASCII |
S6 - Wait Time for Blind Dialling
Contains the value which tells the modem how long to wait for a dial tone, from the time it picks up the handset until it starts to dial a telephone number. If difficulty in dialling is detected try increasing this value. You should hear a dial tone through the speaker in the Modem before dialling commences.
| Default: | 4 |
| Range: | 2..255 |
| Units: | seconds |
S7 - Wait for Carrier After Dial
Contains the value which tells the modem how long to wait for a carrier from the remote modem after dialling of the telephone number is complete. This value may need to be increased if dialing international telephone numbers.
| Default: | 50 |
| Range: | 1..255 |
| Units: | seconds |
S8 - Pause Time for Dial Delay
Tells the Modem how long to pause when it encounters a comma (,) in the dial string. This would be used when dialling out of a PABX system, where a secondary dial tone must be encountered before dialling is recommenced.
| Default: | 2 |
| Range: | 0..255 |
| Units: | seconds |
S9 - Carrier Detect Response Time
The value of how long the carrier must be present before it is recognised.
| Default: | 6 |
| Range: | 1..255 |
| Units: | tenths of a seconds |
S10 - Lost Carrier to Hang Up Delay
The value of how long to wait between loss of carrier and hanging up the telephone line.
| Default: | 14 |
| Range: | 1..255 |
| Units: | tenths of a seconds |
The duration of the DTMF tones used for dialing.
| Default: | 70 |
| Range: | 70..110 |
| Units: | milli seconds |
The length of the escape code guard time. This is the length of time that must pass before an escape code character will be recognised, preventing escape code characters embedded in a transmission from being interpreted as an escape code sequence.
| Default: | 50 |
| Range: | 0..255 |
| Units: | milli seconds |
S14 - Bit Mapped Command Options
BIT VALUE OPTION DEFAULT = 138
| Bit 0 Not used. | |
| Bit 1 Local Character ECHO | 0 Local ECHO Disabled (E0) 1 Local ECHO Enabled (E1) |
| Bit 2 Quiet Mode | 0
Quiet Mode Enabled (Q0) 1 Quiet Mode Disabled (Q1) |
| Bit 3 Result Codes | 0
Numeric Result (V0) 1 Verbose Result (V1) |
| Bit 4 Not used | |
| Bit 5 Tone or Pulse | 0
Tone Dial (T)
1 Pulse Dial (P) |
| Bit 6 Not used | |
| Bit 7 Originate/Answer | 0 Answer
1 Originate |
Indicates the test in progress. The TSTIND output is turned ON when S16 is non-zero to indicate that a test is in progress. The AT&T0 command terminates any test and sets S16 to zero.
BIT VALUE OPTION DEFAULT = 0
| Bit 0 Local Analog Loopback | 0 Local Analog Loopback Disabled 1 Local Analog Loopback Enabled (&T1) |
| Bit 1 Not used | |
| Bit 2 Local Digital Loopback | 0 Local Digital Loopback Disabled
1 Local Digital Loopback Enabled (&T3) |
| Bit 3 Remote Digital Status | 0 Remote Digital Loopback Disabled 1 Remote Digital Loopback Enabled |
| Bit 4 RDL Request (AT&T6) | 0 Remote Digital Loopback Status - Loopback off 1 Remote Digital Loopback Status - Loopback in progress (&T6) |
| Bit 5 RDL with self test | 0 Remote Digital Loopback with Self Test Disabled 1 Remote Digital Loopback with Self Test Enabled (&T7) |
| Bit 6 Local analog loopback with self test | 0 Local Analog Loopback with Self Test
Disabled 1 Local Analog Loopback with Self Test Enabled (&T8) |
| Bit 7 Not used |
Sets the length of time the modem conducts a test before returning to the command mode. If this register is zero, the test will not automatically terminate; the test must be terminated from the command mode by issuing AT&T0 or ATH command.
| Default: | 0 |
| Range: | 0..255 |
| Units: | seconds |
S21 - Bit Mapped Command Options
BIT VALUE OPTION DEFAULT = 52
| Bit 0 Set by &Jn - otherwise ignored | 0 Jack Select (&J0) 1 (&J1) |
| Bit 1 Reserved | |
| Bit 2 CTS behaviour | 0
CTS tracks RTS (&R0)
1 CTS is always on (&R1) |
| Bit 3,4 DTR behaviour | 0 DTR ignored (&D0) 1 Go to command state if on to-off transition on DTR (&D1) 2 Go on-hook-on if on to off transition on DTR (&D2) 3 Go to initialisation state if on to off transition on DTR (&D3) |
| Bit 5 RLSD (DCD) behaviour | 0 DCD interchange circuit kept on (&C0) 1 Track carrier from remote modem (&C1) |
| Bit 6 DSR behaviour | 0
DSR always active (&S0) 1 DSR is turned on at the start of handshaking. (&S1) |
| Bit 7 Long Space disconnect | 0 Disable Long Space Disconnect (Y0) 1 Enable Long Space Disconnect (Y1) |
S22 - Bit Mapped Command Options
BIT VALUE OPTION DEFAULT = 119
| Bit 0,1 Speaker Volume | 0 Lowest speaker volume (L0) 1 Low speaker volume (L1) 2 Medium speaker volume (L2) 3 High speaker volume (L3) |
| Bit 2,3 Speaker Control | 0 Speaker always off (M0) 1 On during dialling (M1) 2 On always (M2) 3 On until DCD but off during dialling (M3) |
| Bit 4-6 Limit Result Codes | 0 Result options (X0) 4 (X1) 5 (X2) 6 (X3) 7 (X4) |
S23 - Bit Mapped Command Options
BIT VALUE OPTION DEFAULT = N/A
| Bit 0 Remote Digital Loopback | 0 Remote Digital Loopback Disabled (&T5) 1 Remote Digital Loopback Enabled (&T4) |
| Bit 1,2,3 Local DTE communication rate | 0 0-300bps 1 600 bps 2 1200 bps 3 2400 bps 4 4800 bps 5 9600 bps 6 19200 bps 7 38400 bps or higher |
| Bit 4,5 Parity Option | 0 Even 1 Not used 2 Odd 3 None/Mark |
| Bit 6,7 Guard Tone | 0
No guard tone (&G0) 1 Reserved (&G1) 2 1800 Hz guard tone (&G2) |
Expiration of this timer due to lack of modem activity (line activity or DTE activity) will cause the modem to enter its low-power sleep mode. A value of 0 or 255 will disable sleep mode entry.
| Default: | 0 |
| Range: | 0..255 |
| Units: | seconds |
A change in DTR (ON or OFF) that persists for a period shorter than the value held in S25, is ignored by the modem while in data mode. Please refer to the &D setting for the operation of DTR after the value of S25 has been exceeded.
| Default: | 5 |
| Range: | 0..255 |
| Units: | one hundredths of a second for Async & seconds for operation |
S26 - RTS to CTS Delay Interval
Pertains to synchronous operation only. When CTS tracks RTS (AT&R0) and the modem detects an ON to OFF transition on RTS, this register sets the time delay before the modem turns CTS on.
| Default: | 1 |
| Range: | 0..255 |
| Units: | milli seconds |
S28 - Bit Mapped Command Options
BIT VALUE OPTION DEFAULT = 8
| Bit 0 Not used | |
| Bit 1 | 0 75 bps
transmit/1200 bps receive (%F1) 1 1200 bps transmit/75 bps receive (%F2) |
| Bit 2 Reserved | |
| Bit 3,4 Pulse Dialling | 0 Make/Break ratio 39%-61% @ 10pps (&P0)
1 Make/Break ratio 33%-67% @ 10pps (&P1) 2 Make Break ratio 39%-61% @ 20pps (&P2) 3 Make/Break ratio 33%-67% @ 20pps (&P3) |
| Bit 6-7 MNP Negotiation speed | 0 Link negotiation at highest speed (*H0) 1 Link negotiation at 1200 bps (*H1) 2 Link negotiation at 4800 bps (*H2) |
Records the period for which modem will go on hook if the ! modifier is encountered in the dial string.
| Default: | 25 |
| Range: | 0..255 |
| Units: | 10s of milli seconds |
The length of time that the modem will wait before disconnecting when no data is sent or received. In MNP or V.42 mode, any data transmitted or received will reset the timer. In other modes, any data transmitted will reset the timer.
| Default: | 0 |
| Range: | 0..255 |
| Units: | tens of seconds |
S31 - Bit Mapped Auto Fallback Character
BIT VALUE OPTION DEFAULT = 198
| Bit 0 Not used | |
| Bit 1 Automode detection | 0 Disable (N0) 1 Enable (N1) |
| Bit 2,3 Connect Message control | 0 DTE speed only reported (W0) 1 DTE & DCE speed reported (W1) 2 DCE speed only reported (W2) |
| Bit 4-7 Not used |
Records the character to be recognised and used as the XON flow control character.
| Default: | 17 |
| Range: | N/A |
| Units: | N/A |
Record the character to be recognised and used as the XOFF flow control character.
| Default: | 19 |
| Range: | N/A |
| Units: | N/A |
S36 - Negotiation Failure Treatment
This register is read when the S48 register contains the value 128 or if an attempted error correction link fails. These fallback options are initiated immediately upon connection if S48=128.
| Default: | 7 |
| Range: | 0..7 |
| Units: | N/A |
S36=0 Modem disconnects.
S36=1 Modem stays online and a Direct mode connection is established.
S36=2 Not used.
S36=3 Modem stays online and a Normal mode connection is established.
S36=4 An MNP connection is attempted and if it fails, the modem disconnects.
S36=5 An MNP connection is attempted and if it fails, a Direct mode connection is established.
S36=6 Not used.
S36=7 An MNP connection is attempted and if it fails, a Normal mode connection is established.
If an invalid number is entered, the number is accepted into the register, but S37 will act as if the default value is entered.
| Default: | 0 |
| Range: | 0..7 |
| Units: | N/A |
S37=0 Attempt to connect at speed of last
AT command issued. For DTE speeds greater than 14,400
the modem will attempt to connect at 14,400 bps.
S37=1-3 Attempt to connect at 300 bps.
S37=4 Not used.
S37=5 Attempt to connect at 1200 bps.
S37=6 Attempt to connect at 2400 bps.
S37=7 Attempt to connect at V.23
S37=8 Attempt to connect at 4800 bps.
S37=9 Attempt to connect at 9600 bps.
S37=10 Attempt to connect at 12000
bps.
S37=11 Attempt to connect at 14400 bps.
S37=12 Attempt to connect at 7200 bps.
S38 - Delay Before Forced Hangup (ARQ Mode Only)
Specifies the delay between the modem's receipt of the ATH command to disconnect (or ON to OFF transition of DTR if the modem is programmed to follow the signal) and the disconnect operation. For an error correction connection, this register can be used to ensure that data in the modem buffer is sent before the modem disconnects.
If set between 1 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 will be OK.
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.
| Default: | 20 |
| Range: | 0..255 |
| Units: | seconds |
BIT VALUE OPTION DEFAULT = 3
| Bit 0-2 Flow Control Options | 0 No Flow Control 3 RTS/CTS Flow Control (&K3) 4 XON/XOFF Flow Control (&K4) 5 Transparent XON/XOFF (&K5) 6 Both RTS/CTS & XON/XOFF Flow Control (&K6) |
| Bit 3-7 Reserved |
S40 - Bit Mapped Command Options
BIT VALUE OPTION DEFAULT = 105
| Bit 0,1 MNP10 Extended Services | 0 Disable extended services (-K0) 1 Enable extended services (-K1) 2 Enable extended services (-K2) |
| Bit 2 Power Level Adjustment for Cellular use | 0 Auto adjustment ) (M0) 1 Force adjustment) (M1) |
| Bit 3-5 Break Handling (\Kn) | 0 \K0 1 \K1 2 \K2 3 \K3 4 \K4 5 \K5 |
| Bit 6-7 MNP Block Size | 0 64 Chars (\A0) 1 128 Chars (\A1) 2 192 Chars (\A2) 3 256 Chars (\A3) |
S41 - Bit Mapped Options (MNP)
BIT VALUE OPTION DEFAULT = 131
| Bit 0 & 1 Compression Selection | 0 Disable data compression (%C0) 1 MNP5 only (%C1) 2 V.42bis only (%C2) 3 MNP5 and V.42bis (%C3) |
| Bits 6 & 2 Enable auto retrain. Fallback/Fallforward | 0 0 Retrain and Fallback/Fallforward
Disabled (%E0) 0 1 Retrain enabled (%E1) 1 0 Fallback/Fallforward enabled (%E2) |
| Bit 3 Modem to Modem flow control | 0 Disabled (\G0) 1 Enabled (\G1) |
| Bit 4 Initiates stream or block mode. | 0 Stream Mode* (\L0) 1 Block Mode (\L1) |
| Bit 5 Reserved | |
| Bit 7 Fallback to V.22bis/V.22 | 0 Disable fallback (-Q0)
1 Enable fallback (-Q1) |
S46 - V.42bis Compression Selection
Controls selection of compression. The following actions are executed for given values:
S46 = 136 Execute error correction protocol with
no compression.
S46 = 138 Execute error correction protocol with compression.
In addition to V.42bis, the modem also implements MNP5 data compression. V.42bis is used only with LAP-M, and MNP5 only with MNP4.
| Default: | 138 |
| Range: | 136, 138 |
| Units: | N/A |
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 by bypassed if desired.
If an invalid number is entered, it is accepted into the S register, but S48 will act as if 128 is entered.
S48 = 0 Disabled negotiation; bypass the detection and negotiation phases; and proceed with LAP-M.
S48 = 7 Enable negotiation.
S48 = 128 Disable negotiation; bypass the detection and negotiation phases; and proceed at once with the fallback action specified in S36. Can be used to force MNP.
| Default: | 7 |
| Range: | 0, 7 or128 |
| Units: | N/A |
Break signals provide a way for the user to get the attention of the remote modem. If an invalid number is entered S82 will act as if the default value is entered. LAP-M specifies three methods of break signal handling:
S82 = 3 Expedited: Modem sends a break immediately. Data integrity is maintained both ahead of and after the break.
S82 = 7 Destructive: Modem sends a break immediately. Data being processed by each modem at the time of the break is destroyed.
S82 = 128 In Sequence: Modem sends a break in sequence with any transmitted data; data integrity is maintained both ahead of and after the break (factory default).
Note: For the Modem this register is incorporated for compatibility purposes only. Changing this register will not have any affect on the setting of this register.
| Default: | 128 |
| Range: | 3, 7 or 128 |
| Units: | N/A |
Sets the transmit level when communication in data mode over the Public Switch Telephone Network (PSTN).
| Default: | 10 |
| Range: | 6-15 |
| Units: | dBm |
Sets the transmit level when communication in fax mode over the Public Switch Telephone Network (PSTN)
| Default: | 10 |
| Range: | 6-15 |
| Units: | dBm |
The bits in S95 can be set to override some of the ATWn command options. A bit set to a 1 will enable the corresponding result code regardless of the ATWn setting.
Bit 0 - CONNECT result indicating port speed.
Bit 1 - Append \ARQ to verbose CONNECT speed.
Bit 2 - Send CARRIER message.
Bit 3 - Send PROTOCOL message.
Bit 4 - Not used
Bit 5 - Send COMPRESSION result code.
Bit 6,7 -Not used
| Default: | 0 |
| Range: | 0..255 |
| Units: | N/A |
| Numeric response | Word Code | Description |
0 | OK | The command was executed without error. |
1 | CONNECT | The carrier was detected and connection established to a remote computer. |
2 | RING | Telephone ring detected. |
3 | NO CARRIER | Carrier has been lost or was never detected. |
4 | ERROR | Invalid character entered in the command line or command line exceeds 40 characters. |
5 | CONNECT 1200 | Connection at 1200 bps. |
6 | NO DIALTONE | Dial modifier has been used and no dial tone is detected within the period set by S6 (2 seconds). The result code command X1 or X4 is in effect and no dial tone is detected within 5 seconds of going off hook. |
7 | BUSY | Busy signal is detected. |
8 | NO ANSWER | No silence detected when dialling a via a system that does not provide dial tone. |
9 | CONNECT 0600 | Connected at 600 bps. |
10 | CONNECT 2400 | Connected at 2400 bps. |
11 | CONNECT 4800 | Connected at 4800 bps. |
12 | CONNECT 9600 | Connected at 9600 bps. |
13 | CONNECT 7200 | Connected at 7200 bps. |
14 | CONNECT 12000 | Connected at 12000 bps. |
15 | CONNECT 14400 | Connected at 14400 bps. |
16 | CONNECT 19200 | Connected at 19200 bps. |
17 | CONNECT 38400 | Connected at 38400 bps. |
18 | CONNECT 57600 | Connected at 57600 bps. |
19 | CONNECT 115200 | Connected at 115200 bps |
| 20 | CONNECT 230400 | Connected at 230400 bps (56K modems only) |
22 | CONNECT 1200RX/75TX | Connected at 1200/75 bps. |
23 | CONNECT 75RX/1200TX | Connected at 75/1200 bps. |
33 | FAX | |
35 | DATA | Connected as Data modem during auto answer |
40 | CARRIER 300 | Carrier at 300 bps |
44 | CARRIER 1200/75 | Carrier at 1200/75 bps |
45 | CARRIER 75/1200 | Carrier at 75/1200 bps |
46 | CARRIER 1200 | Carrier at 1200 bps |
47 | CARRIER 2400 | Carrier at 2400 bps |
48 | CARRIER 4800 | Carrier at 4800 bps |
49 | CARRIER 7200 | Carrier at 7200 bps |
50 | CARRIER 9600 | Carrier at 9600 bps |
51 | CARRIER 12000 | Carrier at 12000 bps |
52 | CARRIER 14400 | Carrier at 14400 bps |
53 | CARRIER 16800 | Carrier at 16800 bps |
54 | CARRIER 19200 | Carrier at 19200 bps |
55 | CARRIER 21600 | Carrier at 21600 bps |
56 | CARRIER 24000 | Carrier at 24000 bps |
57 | CARRIER 26400 | Carrier at 26400 bps |
58 | CARRIER 28800 | Carrier at 28800 bps |
59 | CONNECT 16800 | Connect at 16800 bps |
61 | CONNECT 21600 | Connect at 21600 bps |
62 | CONNECT 24000 | Connect at 24000 bps |
63 | CONNECT 26400 | Connect at 26400 bps |
64 | CONNECT 28800 | Connect at 28800 bps |
66 | COMPRESSION: CLASS 5 | MNP 5 Data Compression established |
67 | COMPRESSION: v.42 BIS | V.42 bis Data Compression established |
69 | COMPRESSION: NONE | No Data Compression established |
70 | PROTOCOL: NONE | No Error Correction established |
77 | PROTOCOL: LAPM | V.42 (LAP M) Error Correction established |
78 | CARRIER 31200 | Carrier at 31,200 bps |
79 | CARRIER 33600 | Carrier at 33,600 bps |
80 | PROTOCOL: ALT | MNP 2-4 Error Correction established |
81 | PROTOCOL: ALT CELLULAR | Protocol ALT - Cellular |
84 | CONNECT 33600 | Connected at 33,600 bps |
91 | CONNECT 31200 | Connected at 31,200 bps |
+F4 | +FCERROR | Fax Carrier Error |
Modem Pins | Signal Assignment | 25 pin to 25 pin | 25 pin to 9 pin | 25 pin to 8 pin | 25 pin to 5 pin |
| 1 | Frame Ground | 1 | NA | NA | 3 |
| 2 | Transmit Data | 2 | 3 | 3 | 2 |
| 3 | Receive Data | 3 | 2 | 5 | 4 |
| 4 | Req. to Send | 4 | 7 | 1 | NA |
| 5 | Clear to Send | 5 | 8 | 2 | ties to 8 (modem side only) |
| 6 | Data Set Ready | 6 | 6 | NA | 5 (modem side only) |
| 7 | Signal Ground | 7 | 5 | 4&8 | 3 |
| 8 | Carrier Detect | 8 | 1 | 7 | 8&5 (modem side only) |
| 9 | Pos. Test Volt | 9 | NA | 2 | NA |
| 20 | Data Term. Ready | 20 | 4 | 1 | 1 |
| 22 | Ring Indicator | 22 | 9 | NA | NA |
| Connect 6 & 20 on the modem side 25 pin |
The RS-232 interface enjoys more standardisation than most interface conventions. Some companies have, however, redefined it and in so doing have assumed the burden of supporting their conventions. If the above information does not address your situation, refer to your computer's hardware manual or the store/manufacturer from whom you purchased your computer.
Australian Communications Authority Requirements (Australia Only)
The software supplied with this modem has default settings compliant with the requirements of Austel Technical Standard TS-ØØ2. Adjustment of these settings outside the required limits will void the Austel permit associated with the modem.
Dial Retry Attempts
With the service tone detection enabled (eg. Busy Tone) the unit must not be configured to make more than 1Ø dial attempts to the same telephone number.
With the service tone detection disabled (eg. Busy Tone - ATXØ) the unit must not be configured to make more than 3 dial attempts to the same telephone number.
With dial tone detection disabled (eg. ATXØ) the unit should be configured to dial not less than two seconds after line seizure and not more than 5 seconds after line seizure.
In all of the above cases no further attempts shall be made to connect to the telephone number, until a further period of at least 3Ø minutes has elapsed (this does not apply if the redial sequence is manually restarted).
Call Answering
The modem shall answer an incoming call by seizing the line in not less than 2 seconds from the start of the application of ring signal from the PSTN. (eg. ATSØ=2 or issue ATA after the 2nd ring.)
Internal Modems
Internal modems are designed to operate only within a PC with a screw down lid. Also, telecommunications network voltages exist on the card inside the PC. Therefore the telecommunications line connection (Telecom cable) must be removed before opening the case of the PC.
NOTE
Adjustment of these settings outside the required limits will void the Austel permit associated with the modem. Connection of a non-approved modem to the telecommunications network is an offence under Section 253 of the Telecommunications Act 1991 and may attract a maximum fine of $12,ØØØ.
Telecom Requirements (New Zealand only)
Telecom New Zealand requires you to be aware of the following requirements regarding the connection of your modem to the Public Telephone Network.
FAILURE TO ADHERE TO THE THESE REQUIREMENTS MAY NEGATE THE USERS RIGHTS UNDER THE TELECOM TERMS OF SERVICE
This modem may not provide for the effective hand over of a call to or from other telephones or equipment connected to the same line.
The Operation of this modem on the same line as other telephones or equipment fitted with ring detectors and/or bells (or other audible devices) may cause bell tinkle or noise and may cause the ring detector to falsely trigger. The user is NOT to contact Telecom Faults if this occurs.
Should your modem become damaged in any way, you should immediately disconnect it from the telephone line and return it for repair.
The computer(or other equipment) connected to the RS-232(computer) port of your modem shall be certified to meet the requirements of Reg.18 of the New Zealand Wiring Regulations 1976.
To comply with Telecom New Zealand requirements, it is necessary to add the following to your communication software initialisation string
(Refer to the software installation section):
Setting the SØ register (auto-answer) to SØ=1 or SØ>5 will render this equipment non-compliant with telepermit requirements.
Older Telephone Exchanges
Some older telephone exchanges may require you to issue the &G2 command to enable 18ØØHz guard tone.
This equipment does not provide a guard tone by default. In some circumstances this could cause interference with the telephone network signalling systems, and could result in lost calls.
Telecom will not accept responsibility should such problems occur. Such occurrences will be rare.
Initiation of Outgoing calls
When you initiate a call from the computer (or other equipment) connected to the RS232 (computer) port on your modem , you shall:
i) Not make more than 5 call attempts to the same number within a one hour period
ii) Not wait less that 6Ø seconds between call attempts to the same number
iii) Not make more than a total of 1Ø call attempts to the same
number for any single manual call initiation
iv) Not wait less that 6Ø seconds between automatic calls to different numbers
Note: This equipment shall NOT be set up to make automatic calls to the Telecom 111 emergency service.