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)