Peek Traffic LPM-14-E User manual

Peek Traffic Model LPM-14-E
High Speed Low Power Modem
REFERENCE MANUAL
Peek Traffic, Inc.
©1996, Peek Traffic, Inc. All Rights Reserved Rev. 1, January 16, 1997
1500 North Washington Blvd. Sarasota FL 34236 [phone]

i
TABLE OF CONTENT
1. GENERAL DESCRIPTION................................................................................................................................................................... 1-1
1.1. INTRODUCTION................................................................................................................................................................ 1-1
1.2. FEATURES ........................................................................................................................................................................1-1
1.3. INDICATORS .....................................................................................................................................................................1-1
1.4. INSTALLATION..................................................................................................................................................................1-1
1.5. INSTALLATION..................................................................................................................................................................1-1
2. AT COMMAND SUMMARY..................................................................................................................................................................2-1
3. AT COMMAND SET.............................................................................................................................................................................3-1
3.1. AT COMMAND GUIDELINES............................................................................................................................................. 3-1
3.1.1. AT Commands, DTE Adaption....................................................................................................................3-1
3.1.2. AT Command Format .................................................................................................................................3-1
3.1.3. Escape Code Sequence..............................................................................................................................3-1
3.2. AT COMMAND SET ........................................................................................................................................................... 3-2
3.2.1. AT Commands............................................................................................................................................3-2
A/ - Re-execute Command..............................................................................................................3-2
AT= x - Write to Selected S-Register...............................................................................................3-2
AT? - Read Selected S-Register.....................................................................................................3-2
A - Answer ......................................................................................................................................3-2
Bn - CCITT or Bell...........................................................................................................................3-2
Cn - Carrier Control.........................................................................................................................3-2
Dn - Dial..........................................................................................................................................3-3
En - Command Echo....................................................................................................................... 3-4
Fn - Select Line Modulation............................................................................................................. 3-4
Hn - Disconnect (Hang-Up).............................................................................................................3-4
In - Identification.............................................................................................................................. 3-5
Ln - Speaker Volume.......................................................................................................................3-5
Mn - Speaker Control......................................................................................................................3-5
Nn - Automode Enable.................................................................................................................... 3-5
On - Return to On-Line Data Mode.................................................................................................. 3-5
P - Set Pulse Dial Default................................................................................................................3-6
Qn - Quiet Results Codes Control...................................................................................................3-6
Sn - Read/Write S-Register.............................................................................................................3-6
T - Set Tone Dial Default.................................................................................................................3-6
Vn - Result Code Form.................................................................................................................... 3-6
Wn - Connect Message Control ......................................................................................................3-7
Xn - Extended Result Codes: ..........................................................................................................3-7
Table 3.1 Result Codes ..................................................................................................................................................3-8
Yn - Long Space Disconnect........................................................................................................... 3-8
Zn - Soft Reset and Restore Profile.................................................................................................3-9
3.2.2. AT& Commands..........................................................................................................................................3-9
&Cn - RLSD (DCD) Option.............................................................................................................. 3-9
&Dn - DTR Option...........................................................................................................................3-9
&Fn - Restore Factory Configuration (Profile)..................................................................................3-9
&Gn - Select Guard Tone.............................................................................................................. 3-10
&Jn - Telephone Jack Control.......................................................................................................3-10
&Kn - Flow Control........................................................................................................................ 3-10
&Ln - Leased Line Operation......................................................................................................... 3-10
&Mn - Asynchronous/Synchronous Mode Selection...................................................................... 3-10
&Pn - Select Pulse Dial Make/Break Ratio.................................................................................... 3-11

ii
&Qn - Sync/Async Mode...............................................................................................................3-11
&Rn - RTS/CTS Option.................................................................................................................3-11
&Sn - DSR Override...................................................................................................................... 3-12
&Tn - Test and Diagnostics...........................................................................................................3-12
&V - Display Current Configuration and Stored Profiles................................................................. 3-12
&Wn - Store Current Configuration................................................................................................ 3-13
&Yn - Designate a Default Reset Profile........................................................................................3-13
&Zn=x - Store Telephone Number.................................................................................................3-13
3.2.3. AT% Commands.......................................................................................................................................3-14
%En - Enable/Disable Line Quality Monitor and Auto-Retrain or Fallback/Fall Forward................. 3-14
%L - Line Signal Level................................................................................................................... 3-14
%Q - Line Signal Quality............................................................................................................... 3-14
3.2.4. AT\ Commands.........................................................................................................................................3-15
\Gn - Modem-to-Modem Flow Control (XON/XOFF)...................................................................... 3-15
\Kn - Break Control........................................................................................................................3-15
\Nn - Operating Mode.................................................................................................................... 3-15
3.3. ERROR DETECTION AND DATA COMPRESSION COMMANDS................................................................................... 3-16
3.3.1. AT% Commands.......................................................................................................................................3-16
%C - Enable/Disable Data Compression....................................................................................... 3-16
3.3.2. AT\ Commands.........................................................................................................................................3-16
\An - Select Maximum MNP Block Size.........................................................................................3-16
\Bn - Transmit Break to Remote....................................................................................................3-16
3.4. MNP 10 COMMANDS....................................................................................................................................................... 3-17
3.4.1. AT) Commands......................................................................................................................................... 3-17
)Mn - Enable Cellular Power Level Adjustment.............................................................................. 3-17
*Hn - Link Negotiation Speed........................................................................................................3-17
-Kn - MNP Extended Services....................................................................................................... 3-18
-Qn - Enable Fallback to V.22 bis/V.22..........................................................................................3-18
@Mn - Initial Cellular Power Level Setting.....................................................................................3-18
:E - Compromise Equalizer Enable Command.............................................................................. 3-18
4. S-REGISTERS .....................................................................................................................................................................................4-1
4.1. FACTORY DEFAULTS....................................................................................................................................................... 4-1
4.2. S-REGISTER DEFINITIONS.............................................................................................................................................. 4-1
S0 - Number of Rings to Auto-Answer.............................................................................................4-2
S1 - Ring Counter............................................................................................................................4-2
S2 - Escape Character.................................................................................................................... 4-2
S3 - Carriage Return Character.......................................................................................................4-2
S4 - Line Feed Character................................................................................................................ 4-2
S5 - Backspace Character ..............................................................................................................4-2
S6 - Wait Time for Dial Tone Before Blind Dialing........................................................................... 4-2
S7 - Wait Time For Carrier After Dial............................................................................................... 4-2
S8 - Pause Time For Dial Delay......................................................................................................4-3
S9 - Carrier Detect Response Time.................................................................................................4-3
S10 - Lost Carrier To Hang Up Delay..............................................................................................4-3
S11 - DTMF Tone Duration.............................................................................................................4-3
S12 - Escape Prompt Delay (EPD)..................................................................................................4-3
S13 - Reserved...............................................................................................................................4-3
S14 - General Bit Mapped Options Status.......................................................................................4-3
S15 - Reserved...............................................................................................................................4-4
S16 - General Bit Mapped Test Options Status............................................................................... 4-4
S17 - Reserved...............................................................................................................................4-4
S18 - Test Timer ............................................................................................................................. 4-4

iii
S19 - AutoSync Bit Mapped Options...............................................................................................4-4
S20 - AutoSync HDLC Address or BSC Sync Character................................................................. 4-4
S21 - V.24/General Bit Mapped Options Status...............................................................................4-4
S22 - Speaker/Results Bit Mapped Options Status .........................................................................4-4
S23 - General Bit Mapped Options Status.......................................................................................4-4
S24 - Sleep Inactivity Timer ............................................................................................................4-4
S25 - Delay To DTR........................................................................................................................4-4
S26 - RTS to CTS Delay................................................................................................................. 4-5
S27 - Bit Mapped Options Status....................................................................................................4-5
S28 - Bit Mapped Options Status....................................................................................................4-5
S29 - Flash Dial Modifier Time........................................................................................................4-5
S30 - Disconnect Inactivity Timer....................................................................................................4-5
S31 - Bit Mapped Options Status....................................................................................................4-5
S32 - XON Character ......................................................................................................................4-5
S33 - XOFF Character.....................................................................................................................4-6
S34-S35 - Reserved........................................................................................................................4-6
S36 - LAPM Failure Control.............................................................................................................4-6
S37 - Desired Line Connection Speed.............................................................................................4-6
S38 - Delay Before Forced Hang Up...............................................................................................4-6
S39 - Flow Control Bit Mapped Options Status................................................................................4-7
S40 - General Bit Mapped Options Status.......................................................................................4-7
S41 - General Bit Mapped Options Status.......................................................................................4-7
S46 - Data Compression Control.....................................................................................................4-7
S48 - V.42 Negotiation Action.........................................................................................................4-7
S82 - Break Handling Options......................................................................................................... 4-8
S86 - Call Failure Reason Code......................................................................................................4-8
S91 - PSTN Transmit Attenuation Level.......................................................................................... 4-8
S92 - Fax Transmit Attenuation Level .............................................................................................4-8
S95 - Extended Result Codes.........................................................................................................4-8
S201 - Cellular Transmit Level........................................................................................................4-8
6. FAX CLASS 1 COMMANDS.................................................................................................................................................................5-1
6.1. FAX I/O PROCESSING......................................................................................................................................................5-1
6.1.1. DTE-to-Modem Transmit Data Stream........................................................................................................5-1
6.1.2. Modem-to-DTE Receive Data Stream......................................................................................................... 5-1
6.1.3. Fax Mode Selection ....................................................................................................................................5-1
6.1.4. Fax Origination............................................................................................................................................5-1
6.1.5. Fax Answering ............................................................................................................................................5-1
6.1.6. Fax Control Transmission ...........................................................................................................................5-1
6.1.7. Fax Control Reception.................................................................................................................................5-2
6.1.8. Fax Data Transmission...............................................................................................................................5-2
6.1.9. Fax Data Reception ....................................................................................................................................5-2
6.2. COMMANDS ......................................................................................................................................................................5-3
+FCLASS=n - Select Service Class ................................................................................................ 5-3
+F<command>? - Report Active Configuration................................................................................5-3
+F<command>=? - Report Operating Capabilities ..........................................................................5-3
+FAE=n - Data/Fax Auto Answer ....................................................................................................5-3
+FTS=n - Stop Transmission and Wait ...........................................................................................5-3
+FRS=n - Receive Silence..............................................................................................................5-3
+FTM=n - Transmit Data.................................................................................................................5-3
+FRM=n - Receive Data.................................................................................................................. 5-4
+FTH=n - Transmit Data with HDLC Framing..................................................................................5-4
+FRH=n - Receive Data with HDLC Framing ..................................................................................5-4

1
1. GENERAL DESCRIPTION
1.1. INTRODUCTION
Unlike traditional commercial modems, the Peek LPM-14-E is designed to perform its data
transmission functions in virtually all types of environments. From solar-powered roadside equipment
where the temperature could dip well below freezing to the blazing heat of an industrial production line, the
LPM-14-E functions with equal reliability. This is possible because the LPM-14-E is housed in a rugged,
enamal-coated aluminum chassis which protects both the delicate electronics and its signal integrity. A
very efficient standby mode is also implemented in the hardware of the LPM-14-E to take advantage of the
frequent idle periods typical in all remote data retrieval systems. Additionally, only wide temperature range
components are used to build the LPM-14-E which are then conformal coated, allowing it to function in the
harshest environments.
The LPM-14-E comes with a rich set of features that rival that of our competitors. With its power
consumption of less than 100mW in standby mode and only 3.6 Watts while active, the LPM-14-E is
suited for systems that are powered by solar energy. It will reliably communicate with remote modems at
temperatures ranging from -40C to +80C and up to 95% non-condensing humidity. The LPM-14-E is fully
compatible with the CCITT V.32bis, V.32, V.22bis, V.22, Bell 212A and Bell 103, allowing it to
communicate at speeds from 300 to 14,400 baud with all other CCITT compliant modems on the market.
It also features MNP2-4/V.42 Error Correction and MNP5/V.42bis Data Compression protocols, allowing
the LPM-14-E to perform reliable compressed data transmission at a maximum speed of 19200 baud.
1.2. FEATURES
Listed below are features included in the LPM-14-E.
Powered by 5.5V to 40V DC or 24V AC
Power consumption: 100mW standby and 3.6W active power
Mode control: Active by ringing voltage or activity on RS-232 RD line
Operating Temperature: -40C to +80C
Humidity: 95% non-condensing
Data modem standards: V.32bis at 14,400bps, V.32, V.22bis V.22, V.23, V.21, Bell 212A and 103
Error Correction: MNP 2-4 and V.42 LAPM
Data Compression: MNP 5 and V.42bis LAPM
Fax standards: V.17, V.29, V.27ter and V.21 at 14,400bps
Command set: Hayes AT compatible with extensions and Fax class I and II

2
Figure 1.1
1.3 INDICATORS
The front panel of the LPM-14-E features six LED indicators as shown in Figure 1.1. The STBY
lamp indicates whether the LPM-14-E is in the standby mode or the active mode. When the LPM-14-E is
first powered up, the LPM-14-E enters into the standby mode and flashes the STBY lamp. All other
indicators should be off when the unit is in the standby mode. When the LPM-14-E detects the ringing
voltage or an activity on the RS-232 RD line, it goes into the full power mode and the STBY lamp will go
off. The rest of the lamps are used to indicate various stages during a connecting session with a remote
modem. Table 1.1 lists the indicators and their functions.
TABLE 1.1
INDICATORS FUNCTIONS
STBY In standby mode when flashing; active mode
otherwise
RI Ringing voltage detected
OH Off Hook
CD Carrier signal detected
RD Receiving data from DTE
SD Sending data to the DTE
1.4 INSTALLATION
As with standard modem equipment, the LPM-14-E comes with the required connections on the
back panel to allow it to be connected to any Data Terminal Equipment (DTE). Figure 1.2 shows the
connectors and their functions. An RS-232C cable from the DTE equipment connects to the RS-232 port
as shown. DC supply ranging from 5.5V to 40V can be wired to the supplied power plug with the negative
terminal on the outside shell and the positive terminal connected to the inner recepticle as shown in the
figure. This plug then connects to the power jack on the LPM-14-E. Optionally, the power plug from the
Peek supplied wall mount AC transformer can be connected to the power jack on the LPM-14-E. A Dial-up
line from the local phone company connects to the RJ-11 connector marked “Line,”and a telephone,
which is to be shared with the LPM-14-E on the same dial-up line, can be connected to the RJ-11
connector marked “Phone.”
Figure 1.2
LPM-14-E

3
1.5 MODEM CONTROL
The LPM-14-E communicates with the DTE through the RS-232 connection and can be controlled
by command strings received from the DTE. The command strings are in the form of AT commands.
The string is always preceded by the letters “AT”and ends with the Carriage Return character. The LPM-
14-E uses the “AT”part of the string to sense the different baud rates and line settings that the DTE might
be set at. Section 2 of this manual lists the summary of the AT commands available for the LPM-14-E.
While in the active mode, the LPM-14-E can be in one of its two operating modes—command
mode and data mode. “AT”commands are accepted only when the modem is in the command mode.
The DTE can set various operating parameters that are part of the modem’s profiles while the LPM-14-E
is in the command mode. Also, the DTE can instruct the LPM-14-E to dial a phone number, answer an
incoming call, show the current modem profile, etc. The LPM-14-E can be instructed to enter the data
mode by the Dial, Answer or Online commands. Section 3 will discuss these commands in more detail.
For example, after receiving the “ATD555-1212”command, it dials the phone number and attempts to
connect with the modem at that number. When the remote modem answers and the carrier signal has
been detected, the LPM-14-E goes into the data mode.
In the data mode, the LPM-14-E will send all received data from the remote modem to the DTE.
At the same time, all characters received from the DTE will be transmitted to the remote modem.
Depending on the setting of parameters in the active modem profile, data to be transmitted may be
compressed and/or formatted for automatic error correction. Data received from the DTE will first be
formatted by either MNP 4 or V.42 algorithm for automatic error correction by the remote modem, then
they are compressed by either the MNP 5 or V.42bis algorithm for improved data transmission efficiency.
Data from the remote modem will first be uncompressed by the respective compression protocol—MNP 5
or V.42bis. The LPM-14-E recognizes the type of compression protocol used by inspecting the patterns in
the data. It then tests the data for any transmission errors and applies automatic error correction
procedures to ensure that all remotely received data is accurate. Data to be transmitted are processed in
the manner described above, except the Escape sequence.
An Escape sequence is composed of an Escape character repeated three times, followed by a
brief pause. The Escape character is usually the ‘+’sign but may be modified to any symbol by one of the
AT commands. Once the Escape sequence is received, the LPM-14-E enters the command mode,
waiting for an AT command. At this time, the LPM-14-E can be instructed to re-enter the data mode by
the online command (“ATO”) or to disconnect from the remote modem by the “ATH”command. When
disconnected from the remote modem, the LPM-14-E will be in the command mode, waiting for a
command. If no command is received within 25 seconds, the LPM-14-E will switch to the standby mode
to conserve power.

4
2. AT COMMAND SUMMARY
2.1. BASIC AT COMMANDS
Command Function
A/ Re-execute command.
A Go off-hook and attempt to answer a call.
B0 Select V.22 connection at 1200 bps.
B1 Select Bell 212A connection at 1200 bps.
C1 Return OK message.
Dn Dial modifier.
E0 Turn off command echo.
E1 Turn on command echo.
F0 Select auto-detect mode (equivalent to N1).
F1 Select V.21 or Bell 103.
F2 Reserved.
F3 Select V.23 line modulation.
F4 Select V.22 or Bell 212A 1200 bps line speed.
F5 Select V.22 bis line modulation.
F6 Select V.32 bis or V.32 4800 line modulation.
F7 Select V.32 bis 7200 line modulation.
F8 Select V.32 bis or V.32 9600 line modulation.
F9 Select V.32 bis 12000 line modulation.
F10 Select V.32 bis 14400 line modulation.
H0 Initiate a hang-up sequence.
H1 If on-hook, go off-hook and enter command mode.
I0 Report product code.
I1 Report pre-computed checksum.
I2 Report OK.
I3 Report firmware revision, model, and interface type.
I4 Report response programmed by an OEM.
I5 Report the country code parameter.
I6 Report modem data pump model and code revision.
I7 Reports the DAA code (W-class models only).
L0 Set low speaker volume.
L1 Set low speaker volume.
L2 Set medium speaker volume.
L3 Set high speaker volume.
M0 Turn speaker off.
M1 Turn speaker on during handshaking and turn speaker off while receiving carrier.
M2 Turn speaker on during handshaking and while receiving carrier.
M3 Turn speaker off during dialing and receiving carrier and turn speaker on during answering.
N0 Turn off automode detection.
N1 Turn on automode detection.
O0 Go on-line.
O1 Go on-line and initiate a retrain sequence.
P Force pulse dialing.
Q0 Allow result codes to DTE.
Q1 Inhibit result codes to DTE.
Sn Select S-Register as default.
Sn? Return the value of S-Register n.
=v Set default S-Register to value v.
? Return the value of default S-Register.
T Force DTMF dialing.
V0 Report short form (terse) result codes.
V1 Report long form (verbose) result codes.
W0 Report DTE speed in EC mode.
W1 Report line speed, EC protocol and DTE speed.
W2 Report DCE speed in EC mode.

5
X0 Report basic call progress result codes, i.e., OK, CONNECT, RING, NO CARRIER, NO ANSWER
and ERROR.
X1 Report basic call progress result codes and connections speeds, i.e., OK, CONNECT, RING, NO
CARRIER, NO ANSWER, CONNECT XXXX, and ERROR.
X2 Report basic call progress result codes and connections speeds, i.e., OK, CONNECT, RING, NO
CARRIER, NO ANSWER, CONNECT XXXX, and ERROR.
X3 Report basic call progress result codes and connection rate, i.e., OK, CONNECT, RING, NO
CARRIER, NO ANSWER, CONNECT XXXX, BUSY, and ERROR.
X4 Report all call progress result codes and connection rate, i.e., OK, CONNECT, RING, NO
CARRIER, NO ANSWER, CONNECT XXXX, BUSY, NO DIAL TONE and ERROR.
Y0 Disable long space disconnect before on-hook.
Y1 Enable long space disconnect before on-hook.
Z0 Restore stored profile 0 after warm reset.
Z1 Restore stored profile 1 after warm reset.
&C0 Force RLSD active regardless of the carrier state.
&C1 Allow RLSD to follow the carrier state.
&D0 Interpret DTR ON-to-OFF transition per &Qn:
&Q0, &Q5, &Q6 The modem ignores DTR.
&Q1, &Q4 The modem hangs up.
&Q2, &Q3 The modem hangs up.
&D1 Interpret DTR ON-to-OFF transition per &Qn:
&Q0, &Q1, &Q4,.
&Q5, &Q6 Asynchronous escape.
&Q2, &Q3 The modem hangs up.
&D2 Interpret DTR ON-to-OFF transition per &Qn:
&Q0 through &Q6 The modem hangs up.
&D3 Interpret DTR ON-to-OFF transition per &Qn:.
&Q0, &Q1, &Q4,.
&Q5, &Q6 The modem performs soft reset.
&Q2, &Q3 The modem hangs up.
&F0 Restore factory configuration 0.
&F1 Restore factory configuration 1.
&G0 Disable guard tone.
&G1 Disable guard tone.
&G2 Enable 1800 Hz guard tone.
&J0 Set S-Register response only for compatibility.
&J1 Set S-Register response only for compatibility.
&K0 Disable DTE/DCE flow control.
&K3 Enable RTS/CTS DTE/DCE flow control.
&K4 Enable XON/XOFF DTE/DCE flow control.
&K5 Enable transparent XON/XOFF flow control.
&K6 Enable both RTS/CTS and XON/XOFF flow control.
&L0 Select dial up line operation.
&L1 Select leased line operation.
&M0 Select direct asynchronous mode.
&M1 Select sync connect with async off-line command mode. *
&M2 Select sync connect with async off-line command mode and enable DTR dialing of directory zero. *
&M3 Select sync connect with async off-line command mode and enable DTR to act as Talk/Data
switch. *
&P0 Set 10 pps pulse dial with 39%/61% make/break.
&P1 Set 10 pps pulse dial with 33%/67% make/break.
&P2 Set 20 pps pulse dial with 39%/61% make/break.
&P3 Set 20 pps pulse dial with 33%/67% make/break.
&Q0 Select direct asynchronous mode.
&Q1 Select sync connect with async off-line command mode.
&Q2 Select sync connect with async off-line command mode; enable DTR dialing of directory zero.
&Q3 Select sync connect with async off-line command mode; enable DTR to act as Talk/Data switch.
&Q4 Select Hayes AutoSync mode.
&Q5 Modem negotiates an error corrected link.
&Q6 Select asynchronous operation in normal mode.
&R0 CTS tracks RTS (async) or acts per V.25 (sync).
&R1 CTS is always active.
&S0 DSR is always active.
&S1 DSR acts per V.25.

6
&T0 Terminate any test in progress.
&T1 Initiate local analog loopback.
&T2 Returns ERROR result code.
&T3 Initiate local digital loopback.
&T4 Allow remote digital loopback.
&T5 Disallow remote digital loopback request.
&T6 Request an RDL without self-test.
&T7 Request an RDL with self-test.
&T8 Initiate local analog loop with self-test.
&V Display current configurations.
&W0 Store the active profile in NVRAM profile 0.
&W1 Store the active profile in NVRAM profile 1.
&X0 Select internal timing for the transmit clock.
&X1 Select external timing for the transmit clock.
&X2 Select slave receive timing for the transmit clock.
&Y0 Recall stored profile 0 upon power up.
&Y1 Recall stored profile 1 upon power up.
&Zn=x Store dial string x (to 35) to location n (0 to 3 depending upon modem model).
%E0 Disable line quality monitor and auto retrain.
%E1 Enable line quality monitor and auto retrain.
%E2 Enable line quality monitor and fallback/fall forward.
%L Return received line signal level.
%Q Report the line signal quality.
\G0 Disable modem to modem flow control.
\G1 Enable modem to modem flow control.
\Kn Controls break handling during three states:
When modem receives a break from the DTE:
\K0,2,4 Enter on-line command mode, no break sent to the remote modem.
\K1 Clear buffers and send break to remote modem.
\K3 Send break to remote modem immediately.
\K5 Send break to remote modem in sequence with transmitted data.
When modem receives \B in on-line command state:
\K0,1 Clear buffers and send break to remote modem.
\K2,3 Send break to remote modem immediately.
\K4,5 Send break to remote modem in sequence with transmitted data.
When modem receives break from the remote modem:
\K0,1 Clear data buffers and send break to DTE.
\K2,3 Send a break immediately to DTE.
\K4,5 Send a break with received data to the DTE.
\N0 Select normal speed buffered mode.
\N1 Select direct mode.
\N2 Select reliable link mode.
\N3 Select auto reliable mode.
\N4 Force LAPM mode.
\N5 Force MNP mode.
2.2. ECC COMMANDS
%C0 Disable data compression.
%C1 Enable MNP 5 data compression.
%C2 Enable V.42 bis data compression.
%C3 Enable both V.42 bis and MNP 5 compression.
\A0 Set maximum block size in MNP to 64.
\A1 Set maximum block size in MNP to 128.
\A2 Set maximum block size in MNP to 192.
\A3 Set maximum block size in MNP to 256.
\Bn Send break of n x 100 ms.

7
2.3. MNP 10 COMMANDS
)M0 Disable MNP 10 link negotiation power adjustment.
)M1 Enable MNP 10 link negotiation power adjustment.
)M2 Enable cellular mode without power level adjustment during MNP 10 link negotiation.
*H0 Select MNP 10 link negotiation at highest rate.
*H1 Select MNP 10 link negotiation at 1200 bps.
*H2 Select MNP 10 link negotiation at 4800 bps.
-K0 Disable MNP 10 extended services.
-K1 Enable MNP 10 extended services.
-K2 Enable MNP 10 extended services detection only.
-Q0 Disable MNP 10 fallback to 2400 bps (V.22 bis)/1200 bps (V.22).
-Q1 Enable MNP 10 fallback to 2400 bps (V.22 bis)/1200 bps (V.22).
@M0 Select initial transmit level of -26 dBm.
@M1 Select initial transmit level of -30 dBm.
@M2 Select initial transmit level of -10 dBm.
@M3 - @M10 Select initial transmit level of -10 dBm.
@M11 Select initial transmit level of -11 dBm.
@M12 Select initial transmit level of -12 dBm.
.
.
.
@M30 Select initial transmit level of -30 dBm.
@M31 Select initial transmit level of -31 dBm.
:E0 Disable the compromise equalizer.
:E1 Enable the compromise equalizer.
2.4. FAX CLASS 1
+FCLASS=n Service class.
+FAE=n Data/fax auto answer
+FRH=n Receive data with HDLC framing.
+FRM=n Receive data.
+FRS=n Receive silence.
+FTH=n Transmit data with HDLC framing.
+FTM=n Transmit data.
+FTS=n Stop transmission and wait.

3-1
3. AT COMMAND SET
3.1. AT COMMAND GUIDELINES
The basic AT commands used to control modem operation are defined in this section. These commands are summarized in
section 2. The default values are typical of a fully configured modem supporting all data rates and options.
3.1.1. AT Commands, DTE Adaption
Under AT operation, the serial interfaced modem performs an autobaud/autoparity/autolength function on each AT header entered. The
autolength/autoparity facility can detect 7- or 8-bit characters of even, odd, or no parity with one stop bit.
3.1.2. AT Command Format
A command line is a string of characters sent from a DTE to the modem (DCE) while the modem is in a command mode. A command line
has a prefix, a body, and a terminator. Each command line (with the exception of the A/ command) must begin with the character sequence
AT and must be terminated by a carriage return. Commands entered in upper case or lower case are accepted, but both the A and T must be
of the same case, i.e., “AT”= ASCII 065, 084 or “at”= ASCII 097, 116. The body is a string of commands restricted to printable ASCII
characters (032 - 126). Space characters (ASCII 032) and control characters other than CR (ASCII 013) and BS (ASCII 010) in the command
string are ignored. The default terminator is the ASCII <CR> character. Characters that precede the AT prefix are ignored. The command line
interpretation begins upon receipt of the carriage return character.Characters within the command line are parsed as commands with
associated parameter values. The basic commands consist of single ASCII characters, or single characters preceded by a prefix character
(e.g., “&”), followed by a decimal parameter. Missing decimal parameters are evaluated as 0. The modem supports the editing of command
lines by recognizing a backspace character. When modem echo is enabled, the modem responds to receipt of a backspace or delete by
echoing a backspace character, a space character, and another backspace. The hex value to be used for the backspace character is
programmable through register S5. Values equal to 0 or greater than 127, or the value which corresponds to the carriage return character,
cannot be used for the backspace character. This editing is not applicable to the AT header of a command. A command line may be aborted
at any time by entering < cntrl-x > (18h).The AT sequence may be followed by any number of commands in sequence, except for commands
such as Z, D, or A. Commands following commands Z, D, or A on the same command line will be ignored. The maximum number of
characters on any command line is 39 (including “A”and “T”). If a syntax error is found anywhere in a command line command, the remainder
of the line will be ignored and the ERROR result code will be returned.Most commands entered with parameters out of range will not be
accepted and the ERROR response will be returned to the DTE.Commands will only be accepted by the modem once the previous command
has been fully executed, which is normally indicated by the return of an appropriate result code. Execution of commands D and A, either as a
result of a direct command or a re-execute command, will be aborted if another character is entered before completion of the handshake.
3.1.3. Escape Code Sequence
When the modem has established a connection and has entered on-line data mode, it is possible to break into the data transmission in order
to issue further commands to the modem in an on-line command mode. This is achieved by the DTE sending to the modem a sequence of
three ASCII characters specified by register S2. The default character is ‘+’. The timing of the three characters must comply with specific time
constraints. There is a guard time before the first character (the pre-sequence time), a guard time following the third character (the post-
sequence time), and a guard time-out between the first and second characters and between the second and third characters (the inter-
character time). These times are controlled by the value recorded in register S12.

3-2
3.2. AT COMMAND SET
The modem will respond to the commands detailed below. Parameters applicable to each command are listed with the command description.
The defaults shown for each configuration command are those used in the factory profile.
3.2.1. AT Commands
A/ - Re-execute Command
The modem behaves as though the last command line had been re-sent by the DTE. “A/”will repeat all the commands in the command
buffer.The principal application of this command is to place another call (using the Dial command) that failed to connect due to a busy line, no
answer, or a wrong number. This command must appear alone on a command line. This command should not be terminated by a carriage
return.
AT= x - Write to Selected S-Register
This command writes the value x to the currently selected S-Register. An S-Register can be selected by using the ATSn command. All of the
S-Registers will return the OK response if x is a number.
Result Codes:
OK For all arguments.
AT? - Read Selected S-Register
This command reads and displays the selected S-Register. An S-Register can be selected by using the ATSn command.
Result Codes:
OK For all arguments.
A - Answer
The modem will go off-hook and attempt to answer an incoming call if correct conditions are met. Upon successful completion of answer
handshake, the modem will go on-line in answer mode. If +FCLASS=0 is selected, the modem will enter the connect state after exchanging
carrier with the remote modem. If no carrier is detected within a period specified in register S7, the modem hangs up. Any character entered
during the connect sequence will abort the connection attempt.If +FCLASS=1 or 2 is selected to prepare the modem to answer a Fax call, the
modem will go off-hook in V.21 answer mode. It will generate the V.21 2100 Hz answer tone for 3 ±0.5 seconds and, following a delay of 70
ms, will proceed as if the +FTH=3 command were issued. At any stage up to (but excluding) the +FTH=3 command state, any character will
abort the communication. (See the description of the +FTH command for details.)
Bn - CCITT or Bell
When the modem is configured to allow either option, the modem will select Bell or CCITT modulation for a line speed connection of 300 or
1200 bps according to the parameter supplied. Any other line speed will use a CCITT modulation standard. The parameter value, if valid, is
written to S27 bit 6. (Also, see ATFn command.
B0 Selects CCITT operation at 300 or 1200 bps during Call Establishment and a subsequent connection.
B1 Selects BELL operation at 300 or 1200 bps during Call Establishment and a subsequent connection. (Default)
Result Codes:
OK n = 0 or 1.
ERROR Otherwise.
Cn - Carrier Control
This command is included for compatibility only, and has no effect other than returning a result code. The only valid parameter is 1.Result
Codes:
OK n = 1.
ERROR Otherwise.

3-3
Dn - Dial
This command directs the modem to go on-line, dial according to the string entered and attempt to establish a connection. If no dial string is
supplied, the modem will go on-line and attempt the handshake in originate mode. If +FCLASS=0 is selected, the modem will behave as a
data modem and will attempt to connect to another data modem. The modem will have up to the period of time specified by register S6 or S7
to wait for carrier and complete the handshake. If this time expires before the modem can complete the handshake, the modem will go on-
hook with the NO CARRIER response. This command will be aborted in progress upon receipt of any DTE character before completion of the
handshake.If +FCLASS=1 or 2 is selected, the modem will behave as a facsimile modem and attempt to connect to a facsimile machine (or
modem) by entering the HDLC V.21 channel 2 receive state (as if +FRH=3 had been issued). This command will be aborted upon receipt of
any DTE character if the modem has not finished dialing. In this case, the modem will go on-hook and return to command mode after
displaying the NO CARRIER message. If the modem has finished dialing, it proceeds as if the +FRH=3 command has been issued. (Refer to
the +FRH command to determine how the modem behaves following this stage).
Dial Modifiers. The valid dial string parameters are described below. Punctuation characters may be used for clarity, with parentheses,
hyphen, and spaces being ignored.
0-9 DTMF digits 0 to 9.
•The ‘star’digit (tone dialing only).
# The ‘gate’digit (tone dialing only).
A-D DTMF digits A, B, C, and D.
L Re-dial last number: the modem will re-dial the last valid telephone number. The L must be immediately after the
D with all the following characters ignored.
P Select pulse dialing: pulse dial the numbers that follow until a “T”is encountered. Affects current and subsequent
dialing.
T Select tone dialing: tone dial the numbers that follow until a “P”is encountered. Affects current and subsequent
dialing
S=n Dial the number stored in the directory (n = 0 to 3). (See &Z.)
! Flash: the modem will go on-hook for a time defined by the value of S29.
W Wait for dial tone: the modem will wait for dial tone before dialing the digits following “W”. If dial tone is not
detected within the time specified by S7, the modem will abort the rest of the sequence, return on-hook, and
generate an error message.
@ Wait for silence: the modem will wait for at least 5 seconds of silence in the call progress frequency band before
continuing with the next dial string parameter. If the modem does not detect these 5 seconds of silence before the
expiration of the call abort timer (S7), the modem will terminate the call attempt with a NO ANSWER message. If
busy detection is enabled, the modem may terminate the call with the BUSY result code. If answer tone arrives
during execution of this parameter, the modem handshakes.
& Wait for credit card dialing tone before continuing with the dial string. If bong is not detected within the time
specified by S7, the modem will abort the rest of the sequence, return on-hook, and generate an error message.
, Dial pause: the modem will pause for a time specified by S8 before dialing the digits following “,”.
; Return to command state. Added to the end of a dial string, this causes the modem to return to the command
state after it processes the portion of the dial string preceding the “;”. This allows the user to issue additional AT
commands while remaining off-hook. The additional AT commands may be placed in the original command line
following the “;”and/or may be entered on subsequent command lines. The modem will enter call progress only
after an additional dial command is issued without the “;”terminator. Use “H”to abort the dial in progress, and go
back on-hook.
^ Toggles calling tone enable/disable: applicable to current dial attempt only.
( ) Ignored: may be used to format the dial string.
•Ignored: may be used to format the dial string.
<space> Ignored: may be used to format the dial string.
<i> Invalid character: will be ignored.

3-4
En - Command Echo
The modem enables or disables the echo of characters to the DTE according to the parameter supplied. The parameter value, if valid, is
written to S14 bit 1.
E0 Disables command echo.
E1 Enables command echo. (Default.)
Result Codes:
OK n = 0 or 1.
ERROR Otherwise.
Fn - Select Line Modulation
This command selects the line modulation according to the parameter supplied. The line modulation is fixed unless Automode is selected.
This command interacts with the S37 and the N command. The parameter value, if valid, is written to S37 bits 0-4. To select line modulation,
it is recommended that either the F command, or a combination of the S37 and the N command, be used, but not both.
F0 Selects auto-detect mode. Sets N1 and sets S31 bit 1. In this mode, the modem configures for Automode
operation. All connect speeds supported by the modem are possible according to the remote modem’s
preference. The contents of S37 are ignored as is the sensed DTE speed.
F1 Selects V.21 or Bell 103 according to the B setting as the only acceptable line speed resulting in a subsequent
connection. Sets N0, sets S37 to 1, and clears S31 bit 1. This command is equivalent to the command string:
ATN0S37=1.
F2 Not supported.
F3 Selects V.23 as the only acceptable line modulation for a subsequent connection. Originator is at 75 bps and
answerer is at 1200 bps. Sets N0, sets S37 to 7, and clears S31 bit 1. This command is equivalent to the
command string: ATN0S37=7.
F4 Selects V.22 1200 or Bell 212A according to the B command setting as the only acceptable line speed for a
subsequent connection. Sets N0, sets S37 to 5, and clears S31 bit 1. This command is equivalent to the
command string: ATN0S37=5.
F5 Selects V.22 bis as the only acceptable line modulation for a subsequent connection. Sets N0, sets S37 to 6,
and clears S31 bit 1. This command is equivalent to the command string: ATN0S37=6.
F6 Select V.32 bis 4800 or V.32 4800 as the only acceptable line modulation for a subsequent connection. Sets
N0, sets S37 to 8, and clears S31 bit 1. This command is equivalent to the command string: ATN0S37=8.
F7 Selects V.32 bis 7200 as the only acceptable line modulation for a subsequent connection. Sets N0, sets S37
to 12, and clears S31 bit 1. This command is equivalent to the command string: ATN0S37=12.
F8 Selects V.32 bis 9600 or V.32 9600 as the only acceptable line modulations for a subsequent connection. Sets
N0, sets S37 to 9, and clears S31 bit 1. This command is equivalent to the command string: ATN0S37=9.
F9 Selects V.32 bis 12000 as the only acceptable line modulation for a subsequent connection. Sets N0, sets S37
to 10, and clears S31 bit 1. This command is equivalent to the command string: ATN0S37=10.
F10 Selects V.32 bis 14400 as the only acceptable line modulation for a subsequent connection. Sets N0, sets S37
to 11, and clears S31 bit 1. This command is equivalent to the command string: ATN0S37=11.
Hn - Disconnect (Hang-Up)
This command initiates a hang up sequence.
H0 The modem will release the line if the modem is currently on-line, and will terminate any test (AT&T) that is in
progress. Modulation specific, and error correction protocol specific (S38) processing is handled outside of the
H0 command.
H1 If on-hook, the modem will go off-hook and enter command mode.
Result Codes:
OK n = 0 or 1.
ERROR Otherwise.

3-5
In - Identification
The modem reports to the DTE the requested result according to the command parameter.
I0 Reports product code (e.g., “14400”).
I1 Reports a precomputed checksum (see firmware release notes).
I2 Reports “OK”.
I3 Reports firmware revision (VX.XXX)-model code (A = 64K US, C = 128K US, D = 128K W-Class, E = 64K W-
Class), interface type (S = serial; P = parallel), and MCU model (29 = C29; 39 = C39) (e.g., “V1.297-CS29”).
I4 Reports OEM defined identifier string (e.g., “RC96ACL”) in either Hayes-compatible binary format.
I5 Reports Country Code parameter (e.g., “022”).
I6 Reports modem data pump model and internal code revision (e.g., RC144DPL Rev CE).
I7 Reports the DAA code. (e.g., 000 for US or Canada)
Result Codes:
OK n = 0 to 7.
ERROR Otherwise.
Ln - Speaker Volume
The modem sets the speaker volume control according to the parameter supplied. The parameter value, if valid, is written to S22 bits 0 and 1.
L0 Low volume.
L1 Low volume. (Default.)
L2 Medium volume.
L3 High volume.
Result Codes:
OK n = 0 to 3.
ERROR Otherwise.
Mn - Speaker Control
This command selects when the speaker will be on or off. The parameter value, if valid, is written to S22 bits 2 and 3.
M0 Speaker is always off.
M1 Speaker is on during call establishment, but off when receiving carrier. (Default.)
M2 Speaker is always on.
M3 Speaker is off when receiving carrier and during dialing, but on during answering.
Result Codes:
OK n = 0 to 3.
ERROR Otherwise.
Nn - Automode Enable
This command enables or disables Automode detection. The parameter value, if valid, is written to S31 bit 1.
N0 Automode detection is disabled. A subsequent handshake will be conducted according to the contents of S37
or, if S37 is zero, according to the most recently sensed DTE speed.
N1 Automode detection is enabled. A subsequent handshake will be conducted according to the Automode
algorithm supported by the modem. This command is equivalent to F0. (Default.)
Result Codes:
OK n = 0 or 1.
ERROR Otherwise.
On - Return to On-Line Data Mode
This command determines how the modem will enter the on-line data mode. If the modem is in the on-line command mode, the enters the
on-line data mode with or without a retrain. If the modem is in the off-line command mode (no connection), ERROR is reported.
O0 Enters on-line data mode without a retrain. Handling is determined by the Call Establishment task. Generally, if
a connection exists, this command connects the DTE back to the remote modem after an escape (+++).
O1 Enters on-line data mode with a retrain before returning to on-line data mode.
Result Codes:
OK n = 0 or 1 and a connection exists.
ERROR Otherwise or if not connected.

3-6
P - Set Pulse Dial Default
This command forces pulse dialing until the next T dial modifier or T command is received. Sets S14 bit 5. As soon as a dial command is
executed which explicitly specifies the dialing mode for that particular call (e.g., ATDT...), this command is overridden so that all future dialing
will be tone dialed. (See T command).
Result Code:
OK
Qn - Quiet Results Codes Control
The command enables or disables the sending of result codes to the DTE according to the parameter supplied. The parameter value, if valid,
is written to S14 bit 2.
Q0 Enables result codes to the DTE. (Default.)
Q1 Disables result codes to the DTE.
Result Codes:
OK n = 0 or 1.
ERROR Otherwise.
Sn - Read/Write S-Register
The modem selects an S-Register, performs an S-Register read or write function, or reports the value of an S-Register.
n Establishes S-Register n as the last register accessed.
n=v Sets S-Register n to the value v.
n? Reports the value of S-Register n.
The parameter n can be omitted, in which case the last S-Register accessed will be assumed. The S can be omitted for AT= and AT?, in
which case the last S-Register accessed will be assumed.
For example:
ATS7 establishes S7 as the last accessed register.
AT=40 sets the contents of the last register accessed to 40.
ATS=20 sets the contents of the last register accessed to 20.
If the number “n”is beyond the range of the S-Registers available, the modem will return the ERROR message. The value “v”is “MOD”ed
with 256. If the result is outside the range permitted for a given S-Register the values will still be stored, but functionally the lower and higher
limits will be observed. Input and output are always in decimal format. Note that some S-Registers are read-only.In some cases, writing to the
S-Register will appear to be accepted but the value will not actually be written.
T - Set Tone Dial Default
This command forces DTMF dialing until the next P dial modifier or P command is received. The modem will set an S-Register bit to indicate
that all subsequent dialing should be conducted in tone mode. Note that the DP command will override this command. Clears S14 bit 5. (See
P.)
Result Code:
OK
Vn - Result Code Form
This command selects the sending of short-form or long-form result codes to the DTE. The parameter, if valid, is written to S14 bit 3.
V0 Enables short-form (terse) result codes. Line feed is not issued before a short-form result code.
V1 Enables long-form (verbose) result codes. (Default.)
Result Codes:
OK n = 0 or 1.
ERROR Otherwise.

3-7
Wn - Connect Message Control
This command controls the format of CONNECT messages. The parameter value, if valid, is written to S31 bits 2 and 3. Note that the Wn
command can be overridden by register S95 bits (see S95 description).
W0 Upon connection, the modem reports only the DTE speed (e.g., CONNECT 19200). Subsequent responses are
disabled. (Default.)
W1 Upon connection, the modem reports the line speed, the error correction protocol, and the DTE speed,
respectively. Subsequent responses are disabled.
W2 Upon connection, the modem reports the DCE speed (e.g., CONNECT 14400). Subsequent responses are
disabled.
Result Codes:
OK n = 0, 1, or 2.
ERROR Otherwise.
Xn - Extended Result Codes:
This command selects which subset of the result messages will be used by the modem to inform the DTE of the results of commands.Blind
dialing is enabled or disabled by country parameters. If the user wishes to enforce dial tone detection, a “W”can be placed in the dial string
(see D command). Note that the information below is based upon the default implementation of the X results table. Table 3-1 indicates the
messages which are enabled for each X value.If the modem is in facsimile mode (+FCLASS=1 or 2), the only message sent to indicate a
connection is CONNECT without a speed indication.
X0 Disables monitoring of busy tones; send only OK, CONNECT, RING, NO CARRIER, ERROR, and NO
ANSWER result codes. The value 000b is written to S22 bits 6, 5, and 4, respectively.
X1 Disables monitoring of busy tones; send only OK, CONNECT, RING, NO CARRIER, ERROR, NO ANSWER,
and CONNECT XXXX (XXXX = rate). The value 100b is written to S22 bits 6, 5, and 4, respectively.
X2 Disables monitoring of busy tones; send only OK, CONNECT, RING, NO CARRIER, ERROR, NO DIALTONE,
NO ANSWER, and CONNECT XXXX. The value 101b is written to S22 bits 6, 5, and 4, respectively.
X3 Enables monitoring of busy tones; send only OK, CONNECT, RING, NO CARRIER, ERROR, NO ANSWER,
and CONNECT XXXX. The value 110b is written to S22 bits 6, 5, and 4, respectively.
X4 Enables monitoring of busy tones; send all messages. The value 111b is written to S22 bits 6, 5, and 4,
respectively. (Default.)
Result Codes:
OK n = 0 to 4.
ERROR Otherwise.

3-8
Table 3-1. Result Codes
Short Form Long Form n Value in ATXn Command
0 1 2 3 4
0 OK x x x x x
1 CONNECT x x x x x
2 RING x x x x x
3 NO CARRIER x x x x x
4 ERROR x x x x x
5 CONNECT 1200 1 x x x x
6 NO DIALTONE 3 3 x x x
7 BUSY 3 3 3 x x
8 NO ANSWER x x x x x
9 CONNECT 0600 1 x x x x
10 CONNECT 2400 1 x x x x
11 CONNECT 4800 1 x x x x
12 CONNECT 9600 1 x x x x
13 CONNECT 7200 1 x x x x
14 CONNECT 12000 1 x x x x
15 CONNECT 14400 1 x x x x
16 CONNECT 19200 1 x x x x
17 CONNECT 38400 1 x x x x
18 CONNECT 57600 1 x x x x
22 CONNECT 75TX/1200RX 1 x x x x
23 CONNECT 1200TX/75RX 1 x x x x
24 DELAYED 4 4 4 4 x
32 BLACKLISTED 4 4 4 4 x
33 FAX x x x x x
35 DATA x x x x x
40 CARRIER 300 x x x x x
44 CARRIER 1200/75 x x x x x
45 CARRIER 75/1200 x x x x x
46 CARRIER 1200 x x x x x
47 CARRIER 2400 x x x x x
48 CARRIER 4800 x x x x x
49 CARRIER 7200 x x x x x
50 CARRIER 9600 x x x x x
51 CARRIER 12000 x x x x x
52 CARRIER 14400 x x x x x
66 COMPRESSION: CLASS 5 x x x x x
67 COMPRESSION: V.42 bis x x x x x
69 COMPRESSION: NONE x x x x x
76 PROTOCOL: NONE x x x x x
77 PROTOCOL: LAPM x x x x x
80 PROTOCOL: ALT x x x x x
81 PROTOCOL: ALT-CELLULAR x x x x x
+F4 +FCERROR x x x x x
Note: An ‘x’in a column indicates that the message (either the long form if verbose, or the value only for
short form) will be generated when that particular value of ‘n’(shown at the top of the column) has been
selected by the use of ATXn. If the column is blank, then no message will be generated for that X option.
A numeral indicates which less explicit message (verbose or short form) will be output for that X option.
(Also, see Section 3.3).
Yn - Long Space Disconnect
This command enables/disables the generation and response to long space disconnect. The parameter value, if valid, is written to S21 bit 7.
Y0 Disables long space disconnect. (default.)
Y1 Enables long space disconnect. In non-error correction mode, the modem will send a long space of four
seconds prior to going on-hook. In error correction mode, the modem will respond to the receipt of a long space
(i.e., a break signal greater than 1.6 seconds) by going on-hook.
Result Codes:
OK n = 0 or 1.
ERROR Otherwise.

3-9
Zn - Soft Reset and Restore Profile
The modem performs a soft reset and restores the configuration profile according to the parameter supplied. If no parameter is specified,
zero is assumed.
Z0 Soft reset and restore stored profile 0.
Z1 Soft reset and restore stored profile 1.
Result Codes:
OK n = 0 or 1.
ERROR Otherwise.
3.2.2. AT& Commands
&Cn - RLSD (DCD) Option
The modem controls the RLSD output in accordance with the parameter supplied. The parameter value, if valid, is written to S21 bit 5.
&C0 RLSD remains ON at all times. (Default.)
&C1 RLSD follows the state of the carrier.
Result Codes:
OK n = 0 or 1.
ERROR Otherwise.
&Dn - DTR Option
This command interprets the ON to OFF transition of the DTR signal from the DTE in accordance with the parameter supplied. The parameter
value, if valid, is written to S21 bits 3 and 4.
&D0 - DTR drop is interpreted according to the current &Q setting as follows: (Default.)
&Q0,&Q5,&Q6 DTR is ignored. Allows operation with DTEs which do not provide DTR.
&Q1,&Q4 DTR drop causes the modem to hang up. Auto-answer is not affected.
&Q2,&Q3 DTR drop causes the modem to hang up. Auto-answer is inhibited.
&D1 DTR drop is interpreted according to the current &Qn setting as follows:
&Q0,&Q1,&Q4,&Q5,&Q6DTR drop is interpreted by the modem as if the asynchronous escape sequence
had been entered. The modem returns to asynchronous command state without
disconnecting.
&Q2,&Q3 DTR drop causes the modem to hang up. Auto-answer is inhibited.
&D2 DTR drop is interpreted according to the current &Qn setting as follows:
&Q0 through &Q6 DTR drop causes the modem to hang up. Auto-answer is inhibited.
&D3 DTR drop is interpreted according to the current &Qn setting as follows:
&Q0,&Q1,&Q4,&Q5,&Q6DTR drop causes the modem to perform a soft reset as if the Z command were
received. The &Y setting determines which profile is loaded.
&Q2, &Q3 DTR drop causes the modem to hang up. Auto-answer is inhibited.
If &Q5, &Q6, +FCLASS=1 or +FCLASS=2 is in effect, the action taken is the same as for &Q0.
&Fn - Restore Factory Configuration (Profile)
The modem loads the factory default configuration (profile). The factory defaults are identified for each command and in the S-Register
descriptions. A configuration (profile) consists of a subset of S-Registers.
&F0 Restore factory configuration 0.
&F1 Restore factory configuration 1.
Result Codes:
OK
ERROR If the modem is connected.