Fax Modem (250-3581) AT Commands Continued Faxback Doc. # 5799 Continued from Faxback Document # 5797 ATXn EXTENDED RESULT CODES Determines whether the FAX Modem disconnects when it receives a continuous break from a remote FAX Modem for a period equal to, or greater than, 1.6 seconds, and sends a break for 4 seconds before disconnecting due to an ON-to-OFF transition of DTR if an AT&D2 option is in effect, or upon receiving an ATH command. ATY0 = Disable long space disconnect. ATY1 = Enables long space disconnect. ATZn RESULT Causes the FAX Modem to disconnect and performs a warm start. This command must be the last command line. The reset actions are: Clear serial port buffers. Set the baud rate and parity to match the local DTE when any AT command is issued. Restore the active configuration with the user profile denoted by the parameter. AT&Cn DCD OPTION Controls the Received Line Signal Detected (RLSD). [Carrier Detect (DCD)] signal of the serial port. If synchronous mode is selected, this command is ignored and the FAX Modem functions as if the AT&C1 command has been entered. AT&CO = RLSD is always ON regardless of the state of the data carrier from the remote FAX Modem. AT&C1 = FLSD follows the state of the data carrier from the remote FAX Modem. AT&Dn DTR Option Determines actions taken by the FAX Modem in relation to the Data Terminal Ready (DTR) signal of the port. The effect of DTR loss depends upon the AT&D and AT&Q (AT&M) commands. The action file for the even that follows DTR loss is indicated in the following table: &DO &D1 &D2 &D3 &QO NONE 2 3 4 &Q1 1 2 3 4 &Q2 3 3 3 3 &Q3 3 3 3 3 &Q4 1 2 3 4 The DTR-going-off events corresponding to the action numbers in the above table are: 1. FAX Modem disconnects and sends OK result code. 2. FAX Modem goes into command mode if in data mode and sends the OK result code. 3. FAX Modem disconnects, sends the OK result code, and disables auto answer while DTR is OFF. 4. FAX Modem performs a warm start (i.e. same as ATZ command). This is the DTR/AT&D3 abort. AT&F RESTORE FACTORY CONFIGURATION Loads the FAX Modem active configurations area with the factory default values. AT&Gn SET GUARD TONE Normally controls the generation of guard tone. The command is not implemented, however, the command structure is provided for application compatibility. AT&GO = Disable guard tone generation. AT&G1 = Disable guard tone generation. AT&G2 = Enable 1800 Hz guard tone generation. AT&Kn DTE/FAX MODEM FLOW CONTROL Determines how the FAX Modem controls the flow of data between the local DTE and the FAX Modem. When the FAX Modem terminal buffer is full, the FAX Modem will either send an XOFF or drop CTS to stop the data flow. When the buffer is nearly empty, the FAX Modem will either send an XON or raise CTS to start the data flow. The FAX Modem also responds to XON/XOFF characters or RTS stimulus from the DTE by suspending or resuming transmission accordingly. The FAX Modem responds to DTE XON/XOFF characters and also passed the XON/XOFF characters to the remote FAX Modem as data if transparent flow control is selected. When in the Direct mode (AT&QO), flow control is not used and the FAX Modem ignores the setting of this command. AT&KO = Disables RTS/CTS flow control. AT&K3 = Enables RTS/CTS flow control. AT&K4 = Enables XON/XOFF flow control. AT&K5 = Enables transparent XON/XOFF flow control. AT&Ln LINE TYPE Controls selection of leased line or dial-up Line. Although the FAX Modem has only a single line connection, the power level is changed when setting leased line operation (See S91 register). AT&L0 = Dial-up line. AT&L1 = Leased line. AT&Mn COMMUNICATION MODE Same as AT&QO-AT&Q3 AT&Pn DIAL PULES RATIO Selects the ratio of the off-hook (make) to on-hook (break) interval used when pulse dialing. AT&P0 = 39%/61% make/break ratio @ 10 pps. AT%P1 = 33%/67% make/break ratio @ 10 pps. AT&P2 = 39%/67% make/break ratio @ 20 pps. AT&QNn COMMUNICATION MODE The FAX Modem supports three basic communication modes: asynchronous, synchronous, and error correction. Synchronous and Direct modes and not available when the parallel host interface is selected. AT&Q0 = Selects asynchronous operation in the Direct mode. In this mode, the DTE speed must match the telco line speed. AT&Q1 = Selects synchronous mode 1 operation. Supports terminals that are able to communicate in both asynchronous and synchronous protocols. Uses the dial command to place a call in asynchronous mode then switches to synchronous mode once the connection is made. The FAX Modem goes on-hook and switches back to the asynchronous mode when it detects an On-to-OFF transition on DTR or a loss of carrier from the remote FAX Modem exceeding the timer interval given by register S10 (default = 1.4 seconds). AT&Q2 = Selects synchronous FAX Modem 2 operation. Supports synchronous terminals with stored number dialing. The FAX Modem automatically dials a stored number when it detects an ON transition on DTR. An asynchronous terminal is still needed to save or change the phone number stored in the NVRAM; the number is saved using the "AT&Z0=x" command. The FAX Modem dials the number stored in the first entry. The FAX Modem goes on-hook and switches back to the asynchronous mode when it detects an ON-to-OFF transition on DTR or a loss of carrier from the remote FAX Modem exceeding the time interval given by register S10 (default = 1.4 seconds). AT&Q3 = Selects synchronous mode 3 operation. The mode allows DTR to act as a Talk/Data switch. The operator manually initiates a call with DTR OFF, implying the FAX Modem is in Talk mode. To complete the call, the operator switches the FAX Modem to Data mode by turning DTR On after the last number is dialed. The FAX Modem goes On-hook and switches back to the asynchronous mode when an ON-to-OFF transition on DTR is detected or a loss of carrier occurs from the remote FAX Modem exceeding the time interval given by register S10 (default = 1.4 seconds). AT&Q4 = This command causes the FAX Modem to issue OK result code but has no effect on operation. AT&Q5 = Selects error correction mode. FAX Modem negotiates an error- correction link. The FAX Modem can be configured to either disconnect or fallback to a normal asynchronous connection if the link cannot be negotiated (refer to register S36). AT&Q5 and S36 = 0: Same as AT/N2 (no fallback). AT&Q5 and A36 = 1: Same as AT/N3 (fallback) (see AT/N command). AT&Q6 = Selects asynchronous operation In Normal Mode (Speed Buffering). In this mode, the DTE speed can differ from the telcoline speed. AT&Rn RTS/CTS OPTION Controls the state of the CTS signal in the synchronous mode. CTS is always on in the asynchronous mode. AT&RO = CTS tracks RTS. CTS is turned On in response to an OFF-to-ON transition of TRS from the local DTE after a delay period specified by register S26 in increments of 10 milliseconds (default = 0). AT&R1 = The FAX Modem ignores RTS; CTS is held ON. AT&Sn DSR OPTION Determines whether DSR operates in accordance with EIA-232-D specification or remains ON. AT&S0 = DSR is always ON. AT&S1 = DSR is turned ON at start of handshaking and OFF when in test mode or idle state. DSR is turned OFF when carrier is lost. AT&Tn TEST AND DIAGNOSTIC Selects the test command. Test commands must be initiated in the command mode with asynchronous operation in the Direct mode selected (AT&Q0) at a speed of 1200 bps or faster. A telco line connection must be established prior to initiating digital loopback tests. If these conditions are not met, the FAX Modem issues the ERROR result code. If local analog loopback is initiated while the FAX Modem issues the ERROR result code. If local analog loopback is initiated while the FAX Modem is connected, the FAX Modem disconnects before performing the test. AT&T0 = End test in progress. The escape sequence must be issued to return the FAX Modem to the command mode prior to sending this command. Subsequent issuing of the AT0 command while in the operation if the interrupted test was digital loopback. AT&T1 = Initiates local analog loopback. The test verifies the working condition of the path between the local DTE and local FAX Modem. The characters received from the DTE looped back to the DTE by the FAX Modem. AT&T3 = Initiates remote digital loopback locally. The characters received from the remote FAX Modem are looped back to the remote FAX Modem by the local FAX Modem. This test verifies the working condition of the path from a remote FAX Modem, through a local FAX Modem, and back to the remote FAX Modem. AT&T4 = Allows the FAX Modem to respond to a request from a remote FAX Modem for a remote digital loopback test. AT&T5 = Prohibits the FAX Modem from granting a request from a remote FAX Modem for a remote digital loopback test. AT&T6 = Initiates remote digital loopback. The characters received from local DTE are transmitted to the remote FAX Modem and looped back from the remote FAX Modem to the local FAX Modem and DTE. This test verifies the working condition of the path between the local DTE and the remote FAX Modem. AT&T7 = Initiates remote digital loopback with self test. This test works similarly to AT&T6 except that the FAX Modem sends an alternating zeros and ones (0101) test pattern to the remote FAX Modem and continuously examines the validity of the returned data. The FAX Modem increments an internal error counter each time an error is detected. At the end of the test, the FAX Modem returns a 3-digit error count to the DTE. AT&T8 = Initiates local analog loopback. AT&V VIEW CURRENT CONFIGURATION AND USER PROFILES Displays the active configuration and user profiles. AT&Wn STORE USER PROFILE Saves the current configuration into NVRAM as one of two user profiles. The current configuration is comprised of a list of storable parameters as show in Table 2-1. Some of the parameters are illustrated in the AT&V command. These settings are restored to the active configuration upon receiving an ATZn command or at power up (see AT&Y command). The user profile saved is denoted by the parameter value. AT&W0 = Save as user profile 0. AT&W1 = Save as user profile 1. AT&Xn CLOCK SOURCE SELECTION Selects the source of the synchronous transmit clock for the FAX Modem during asynchronous operation. AT&X0 = Internal timing. The FAX Modem generates the transmit clock signal EIA Pin 15 output at the serial interface. AT&X1 = External timing. The local DTE sources the transmit clock signal the EIA Pin 24 input of the serial interface. The FAX Modem applies this clock to the EIA Pin 15 output at the serial interface. AT&X2 = Slave receive timing. The FAX Modem derives the transmit clock signal from the incoming carrier and applies it to the EIA Pin 15 output at the serial interface. AT&Yn DESIGNATE DEFAULT USER PROFILE Designates which of two user profiles will be into the active configuration at power up. The user profiles is denoted by the parameter value. AT&Y0 = Selects user profiles 0. AT&Y1 = Selects user profiles 1. AT&Zn=x STORE PHONE NUMBER Stores a 36-digit dial string (x) in the specified entry (n) for later dialing. (See ATDS=n command). (SMC/all-7/5/94)