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DS-CPC2400E-R03 1
CPC2400E
Embedded Modem Module
Part # Description
CPC2400E 2400 Baud Embedded Modem Module
Applications
Features Description
Ordering Information
Pin Configuration
• Vending/Gaming Machines
• Set Top Box Back Channel
• Direct Broadcast Satellite
• Utility Meters
• Point of Sale Terminals
• Remote Diagnostics
• Remote Telemetry
• Remote Monitoring
• Embedded Applications
• Easy Integration
• Small Footprint 1.00" x 2.50"
• Full Duplex 2400bps
• Low Power Consumption
• V.24 DTE Interface
• Single +5V Supply Operation
• Supported Protocols: V.22bis, V.23, V.22
• UL Recognized Component
• FCC Part 15B Compliant
• FCC Part 68 Approved (User Transferrable)
The CPC2400E is a 2400 baud embedded modem
module intended for applications that require a
data communications link to the Public Switched
Telephone Network (PSTN). The CPC2400E is a
complete module on a small 1.0” x 2.5” printed circuit
board that can be socketed or soldered into the host
system mother board. The module is FCC Part 68
approved and includes a user transferrable registration
number. It also is a UL recognized component. The
CPC2400E can be used in a variety of applications
including set top box back channel communications,
vending machines, remote utility metering, remote
data acquisition, plus a host of other applications.
The CPC2400E supports a standard serial V.24 TTL
interface to the DTE equipment.
Approvals
• UL/C-UL: 174201
• FCC Reg. # LVRPHL-25931-MD-E
Block Diagram
V.22BIS
DATA PUMP
CONTROLLER DAA
PARALLEL
V.24
SERIAL
LINE
INTERFACE
DTE
TIP
RING
AUDIO
OUT
+5V
GND
J1
VCC
GND
-DTR
-DCD
-MUTE
A1
N/C
RXD
TXD
J2 N/C
TIP
N/C
RING
N/C
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CPC2400E
Absolute Maximum Ratings are stress ratings. Stresses
in excess of these ratings can cause permanent damage
to the device. Functional operation of the device at these
or any other conditions beyond those indicated in the
operational sections of this data sheet is not implied.
Exposure of the device to the absolute maximum ratings
for an extended period may degrade the device and effect
its reliability.
Absolute Maximum Ratings @ 25ºC
Parameter Min Max Units
Dielectric Withstanding Voltage - 1000 Vrms
Tip/Ring Current (Continuous) 20 120 mA
Operating Temperature 0 70 ºC
Storage Temperature 0 100 ºC
Relative Humidity (Non-Condensing) 10 85 %
1 Derate linearly 3.33 mW / ºC
Parameter Conditions Min Typ Max Units
DC Electrical Characteristics @ 25ºC
VCC Supply Voltage - 4.75 5 5.25 V
VCC Supply Current - Idle (Sleep Mode) VCC=5V - 5 10 mA
VCC Supply Current - Active VCC=5V - 70 100 mA
Line Matching Impedance VCC=5V - 600 -
Ringing Voltage VCC=5V, f=20Hz - 22 30 Vrms
Ringer Equivalence Number (REN) VCC=5V - 0.6B - -
Telephone Line Loop Current VCC=5V 20 - 120 mA
DTE DC Characteristics @ 25ºC
Input High Voltage VIH - 2 - VCC+0.3 V
Input Low Voltage VIL - 0 - 0.8 V
Input Leakage Current IL GND<VO<VCC -10 - 10 A
Output High Voltage VOH IOH=-2mA, VCC=5V 4 - - V
Output Low Voltage VOL IOH=+2mA, VCC=5V 0 - 0.4 V
Input High Voltage VIH VCC=5.5V 0.7 2.6 VCC+0.3 V
Input Low Voltage VIL VCC=5.5V GND-0.3 1.6 0.2VCC V
Electrical Characteristics
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Definitions
*The Performance data shown in the graphs above is typical of device performance. For guaranteed parameters not indicated in the written specifi cations, please
contact our application department.
Pin I/O Name Function
J1-1 I VCC Connects to external host power source of +5V +/-5%
J1-2 I GND Power supply return
J1-3 I -DTR Data Terminal Ready. An active Low input on this pin indicates that the host system is ready to communicate with the
modem.
J1-4 O -DCD Data Carrier Detect. When active, indicates carrier signal has been detected. For options see AT Command reference
section under &C command.
J1-5 O -MUTE Mutes external speaker. Uses AT “M” command.
J1-6 O A1 Analog output that can be used to monitor modem activity via an external audio amplifi er.
J1-7 - N/C No Connection
J1-8 I RXD Serial data input from host DTE
J1-9 O TXD Serial data output to host DTE
Pin I/O Name Function
J2-1 - NC No Connection
J2-2 I/O TIP Tip connection to telephone line
J2-3 - N/C No Connection
J2-4 I/O RING Ring connection to telephone line
J2-5 - NC No Connection
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CPC2400E
The CPC2400E is a small, full featured, 2400 baud
module intended for embedded applications and is
fully FCC Part 68 approved. The CPC2400E includes
a user transferable FCC registration number which
the end product must display (see section for more
details). The module consists of a Data Access
Arrangement (DAA), V.22bis data pump, and a
microcontroller on a 1.00” x 2.50” PCB.
The CPC2400E connects to the telephone lines
TIP and RING leads and must be made through an
approved RJ-11 jack. The CPC2400E supports the
industry standard AT command set (see AT Command
set section for further details).
The CPC2400E operates off a single +5V supply
and supports low power modes of operation. When
the device is not in use, it automatically enters sleep
mode, reducing supply current to a minimum. An
incoming ring signal from the phone lines powers up
the device (wake-on ring).
An evaluation board is available for testing the
CPC2400E. This evaluation board includes an RS232
line driver, LED status indicators and an amplified
speaker circuit. When used with the evaluation
board, the CPC2400E also meets the FCC Part 15B
emissions test. Contact IXYS IC Division for more
information on the CPC2400E Evaluation Board.
Functional Description
DAA
The DAA portion of the CPC2400E has been
designed to interface directly with the U.S. PSTN
as governed by the FCC. The DAA includes the
circuitry for hookswitch, ring detection, gyrator, surge
protection and analog signal coupling transformer. The
DAA circuitry provides up to 1000 Vrms of longitudinal
surge protection. For countries using a PSTN similar
to the U.S. (Canada, Japan), the product using the
CPC2400E must be submitted to a suitable test house
for approval. Consult IXYS IC Division for further
information.
FCC Part 68: Connecting to the PSTN
1. General
The CPC2400E complies with FCC Part 68 rules
which regulates equipment connected to the
telephone network. The CPC2400E provides a user
transferable Part 68 registration which means that
customers can use IXYS IC Division’s registration
number for the CPC2400E. Customers who wish, can
reregister the modem under their name. Reregistration
assigns the customer a unique registration number.
No additional FCC Part 68 submittal is required for
equipment using the CPC2400E module.
2. Repairs
The FCC requires that IXYS IC Division makes
all necessary repairs to the modem. If you are
experiencing problems with the CPC2400E, call
1-800 272-5273 for further information. If repairs are
necessary after the modem has been installed in your
product and delivered to your customer, the modem
must be returned to you where the CPC2400E can be
removed and sent back to IXYS IC Division.
3. Label Instructions
A label similar to the following should be made visible
on the outside of the end user product.
4. Design Guidelines
The following design guidelines should be followed to
insure compatibility to FCC Part 68 tests:
4.1. The CPC2400E, the RJ-11 jack and the interface
circuitry must be mounted on a PCB the should meet
UL 94V-0 flammability standard.
4.2. Tip and Ring traces from the CPC2400E to the
RJ-
11 jack should be isolated by a minimum of 1.5mm
(0.06in) to prevent breakdown. Traces must have a
minimum
width of 0.5mm (.02in).
4.3. Insure that module is securely installed to the host
system. Vibration and drop tests will loosen
components
that are not securely mounted. One of two methods
for securing the module should be used:
4.3.1 Soldered to the main PCB. This method is well
suited for harsh environments where the end product
may be subjected to shock and vibrationas in
industrial
environments (equipment monitoring, etc.).
4.3.2 Socketed to the main PCB. This method is well
suited for environments where the end product is not
subjected to shock and vibrations as in consumer
applications (set top boxes, etc.).
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4.4. Components used must be able to withstand
temperature and humidity extremes per FCC Part 68.
4.5. When connecting to the PSTN, an FCC approved
telephone jack must be used in the host system and
must meet the mechanical requirements per FCC Part
68.3 Sub-part F. For RJ-11 jacks, refer to FCC Public
Notice #42269 for a list of approved vendors.
4.6. The supplied FCC Registration Number including
REN must be visible on the outside of the end user
product. See Section 3.
5. Exhibit J: User Instructions
Instructions to our customers:
The FCC Part 68 Rules require the following
information (or equivalent) to be provided for the end
user product.
FCC Requirements for Consumer Products
This equipment complies with FCC rules, Part 68. On
the,
[ ] FRONT side [ ] BOTTOM side
[ ] BACK side [ ] TOP side
of this equipment is a label that contains, among other
information, the FCC Registration Number and Ringer
Equivalence Number (REN) for this equipment. If
requested, provide this information to your telephone
company.
The (REN) is useful to determine the quantity of
devices you may connect to your telephone line and
still have all of those devices Ring when your number
is called. In most, but not all areas, the sum of the
REN’s of all devices should not exceed five (5.0). To
be certain of the number of devices you may connect
to your line, as determined by the REN, you should
call your local telephone company to determine the
maximum REN for your calling area.
If this equipment causes harm to the telephone
network, the Telephone Company may discontinue
your service temporarily. If possible, they will notify you
in advance. But if advance notice isn’t practical, you
will be notified as soon as possible. You will be advised
of your right to file a complaint with the FCC.
Your telephone company may make changes in its
facilities, equipment, operations, or procedures that
could affect the proper operation of your equipment. If
they do, you will be given advance notice so as to give
you an opportunity to maintain uninterrupted service.
If you experience trouble with this equipment, please
contact (your company name) at (your company
phone number) for warranty/repair information. The
telephone company may ask that you disconnect
this equipment from the network until the problem
has been corrected or until you are sure that the
equipment is not malfunctioning.
This equipment may not be used on coin service
provided by the telephone company. Connection to
party lines is subject to state tariffs.
FCC rules prohibit the use of non-hearing aid
compatible telephones in the following locations or
applications:
(1) All public or semipublic coin-operated or credit
card telephones.
(2) Elevators, highways, tunnels (automobile, subway,
railroad or pedestrian) where a person with impaired
hearing might be isolated in an emergency.
(3) Places where telephones are specifically installed
to alert emergency authorities such as fire, police, or
medical assistance personnel.
(4) Hospital rooms, residential health care facilities,
convalescent homes, and prisons.
(5) Workstations for the hearing impaired.
(6) Hotel, moel, apartment lobbies; in stores where
telephones are used by patrons to order merchandise;
in public transportation terminals where telephones
are used to call taxis, or to reserve lodging or rental
cars.
(7) Hotel and motel rooms. At least ten percent of
the rooms must contain hearing aid compatible
telephones; or jacks or plug-in hearing-aid compatible
telephones which will be provided to hearing impaired
customers upon request.
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CPC2400E
Figure 1 is a schematic of the CPC2400E in a
typical host system application. The host system
communicates to the CPC2400E through a standard
V.24 serial interface. Refer to the Pinout and
Definitions section for functional descriptions of the
pins. The transmit and receive data is sent over the
TXD and RXD pins. The -DCD and -DTR pins are
used for handshaking. The audio output pin, A1 is
used for monitoring the analog data and can be
amplified to drive a speaker. The -MUTE can be used
to enable or disable the speaker.
Applications
The ferrite beads FB1 and FB2 may be required to
reduce EMI emissions per FCC Part 15. Determining
the value for the ferrite beads depends solely on the
emissions generated by the end user product.
Figure 2 is a schematic of the CPC2400E in a
standalone RS232C configuration. This circuit uses
the Linear Technologies LT1181A RS232 line driver.
Note that the LT1181A line driver inverts the signals.
Both figures 1 and 2 are for reference purposes only.
Exact component values should be determined by the
user.
CPC2410E
MODEM
TIP
RING TELEPHONE
LINE
FB1
FB2
HOST
SYSTEM
SPEAKER AUDIO AMP
RXD
TXD
-DCD
-DTR
-MUTE
A1
+5V
VCC
GND
CPC2400E
MODEM
TIP
RING
TELEPHONE
LINE
FB1
FB2
RXD
TXD
LT1181A
1
13
2
3
4
5
6
7
8
9
10
11
12
17
14
15
16
18
20
19
21
22
24
23
25
TXD
RXD
811
910
15
14
13
12
16
2
4
5
6
+5V
17
3
18
7
DB25F
RS232 DRIVER
+5V
VCC
GND
Figure 1. CPC2400E System Environment
Figure 2. Stand Alone Modem with RS232C Interface
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Command lines are typed to the modem from the
terminal when the modem is in the Idle or Command
state. The modem does not execute any of the
commands in a command line until after the command
line is ended by the end of line character <CR>. A
command line is a string of char-acters starting with
the A and T characters and ending with a special
end of line character, <CR>. Characters typed before
the AT are ignored. Command lines contain at most
40 characters after the AT, not counting spaces. The
modem does not execute any of the commands in a
command line that is too long.
To Echo command line characters, use the E1
command.
Typing mistakes can be aborted by using a special
Back-Space character, <BS>, after the initial A and T
characters have been entered.
A partial command line can be aborted by typing a
Ctrl-X character. The modem returns an OK result
code and ignores the partial AT command line.
Command lines may contain several commands
one after another. The Answer (A), Dial (D), and Go
On-Line (O) commands usually cause any following
commands in the command line to be ignored.
Command Line Execution
The characters in a command line are executed one
at a time. Any unexpected characters, except control
characters, stop command line execution and return
an ERROR result code. Unexpected characters
include numbers out-side the range of values
accepted by the command. All control characters
in a command line except Ctrl-X and the special
characters such as <CR> and <BS> are ignored.
The numerical argument of a command is assumed
to be 0 if it was not provided. For example, the
commands ATH<CR> and ATH0<CR> both hang up
the telephone line.
When the modem has executed a command line the
result code of the last command executed is returned
to the terminal. If the value to be written to a modem
S-register is outside the range of values accepted
by the S-register then its value is set to the nearest
allowed value.
Leading zeros in numeric arguments, including
S-register numbers, are ignored. For example,
ATS1=2 and ATS01=2 both set S-register S1 to 2.
All numeric arguments, including S-register numbers,
are decimal (base 10).
AT Command Prefix
Each modem command line begins with the letters
A and T. The modem uses these characters to
determine the data rate and parity of data from the
terminal.
A/Repeat Last Command
To repeat the commands in the last command line
type the letters A and / instead of A and T.
<CR>End Of Line Character
This character is typed to end a command line. The
value of the <CR> character is stored in S-register S3.
The de-fault is 13, the ASCII carriage return character.
When the <CR> character is entered, the modem
executes the commands in the command line.
Note: default values in the AT Command Tables are
denoted by bold face type.
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CPC2400E
Command Function and Description
A Answer The A command makes the modem go off hook and respond to an incoming call. Use this command after the
modem has returned the RING result code.
If the modems successfully complete the answering process they each return a CONNECT result code and enter the
On-Line state.
If no transmit carrier signal is received from the calling modem within the time specifi ed in S-register S7, the modem
hangs up, returns the NO CARRIER result code, and enters the Idle state.
Any commands following the answer command on the command line are ignored.
This command is aborted if a key is pressed before the answer process is completed, or when DTR is off if some
options in the &Q or &D commands have been used.
B Communication
Standard Option
The B command tells the modem which special telephone line modulation standards to use. The modem can be
confi gured to use:
B0 Use the ITU-T modulation standards for all telephone line data rates. This includes V.22 for the
1200 bps telephone line data rate and V.21 for the 300 bps telephone line data rate.
B1 Not Supported
&C Data Carrier
Detect Options
&C determines how the modem’s DCD signal relates to the carrier signal from the other modem. This
option takes effect only at the beginning of a telephone line connection. If &C is issued from the
Command state it will not have an immediate effect.
&C0 During asynchronous operation (&Q0 in effect) DCD is on at all times. During synchronous operation
(&Q1) DCD refl ects the state of the carrier signal from the other modem using S-registers S9 and S10.
This is the default value in North America.
&C1 Refl ects the state of the carrier signal from the other modem using S-registers S9 and S10.
D Dial The D command makes the modem dial a telephone call according to the digits and dial modifi ers in the dial string
following the command. Any commands following the dial string on a command line are ignored unless the semicolon
dial modifi er is the last character in the dial string. If the modem was already off hook when the Dial command
was given, the modem dials immediately without trying to detect a dial tone. Characters other than digits and dial
modifi ers in a dial string are ignored, but are counted as characters in the command line buffer.
If line current sensing is enabled, and line current is detected before the modem is taken off-hook when the modem
needs to dial, a NO CARRIER result code is displayed and the modem enters the Idle state. If the modem does not
need to dial (i.e., ATD with no dial string), the modem assumes the call was manually established and attempts to
make a connection.
The D command is not valid when the modem is in the On-Line state.
See DIAL MODIFIERS and MODEM RESULT CODES for more information.
AT Command Set
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AT Command Set
Command Function and Description
&D Data Terminal &D determines how the modem responds to the DTR signal from the terminal. The country Ready
Options confi guration may prevent the modem from detecting terminal DTR. In this case, the modem assumes DTR
is always on. In North America, terminal DTR is normally detected. If DTR detection has been prevented, the modem
will respond with an ERROR result to this command.
The response to changes in DTR also depends on the &Q and &D commands. This table defi nes what happens
when DTR goes off for all possible combinations of the &D and &Q commands. To see what happens when DTR
goes on refer to the &Q command. The default value is &D0 in North America:
&D0 &D1 &D2 D3
&Q0 None B C D
&Q1 A B C D
A The modem hangs up the telephone line and issues an OK result code.
B If in the On-Line state, the modem goes into the Command state and issues an OK result code.
C The modem hangs up the telephone line and issues an OK result code. Auto-Answer is disabled as
long as DTR stays off.
D The modem resets.
E Command Mode E tells the modem whether or not to echo characters sent from the terminal when the modem is
Character Echo accepting AT commands.
E0 Does not echo characters sent from the terminal.
E1 Echo characters sent from the terminal. This is the default value in North America.
%E Automatic Retrain
Options
The %E command controls whether the modem will initiate retrain with the other modem during a telephone line
connection during operation in data modes supporting retrain. The modem always responds to a retrain operation
initiated by the remote modem. The modem can be forced to initiate a retrain by the On-Line (O1) command.
%E0 Do not initiate a retrain.
%E1 Initiate a retrain if the datapump indicates one is required.
&F Recall Factory
Profi le
&F changes these AT command options and S-registers to their default values. The default values may be changed
for use in different countries. The values for North America are:
S-registers
S0=0 S1=0 S2=43 S3=13 S4=10 S5=8
S6=2 S7=30 S8=2 S9=6 S10=14 S11=95
S12=50 S17=10 S25=5 S28=0 S29=25 S37=0
Commands
B1 E1 M1 P Q0 V1 X4 &C0 &D0 &G0 &P0 &Q0 %E1
&G Guard Tone
Options
&G tells the modem which guard tone to transmit when the modem is transmitting the high band (i.e., answer
handshake and answer mode).
&G0 No guard tone. This is the default value in North America.
&G1 550 Hz guard tone (V.22 and V.22bis only)
&G2 1800 Hz guard tone (V.22 and V.22bis only)
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CPC2400E
AT Command Set
Command Function and Description
H Hook H0 Hang up the telephone line.
H1 Go off hook without answering a telephone call. This may be disabled in countries prohibiting its use.
&HT PTT Test
Command
The &HT command causes the modem to transmit tones for PTT testing. The test tone is generated until a character
is typed on the modem’s terminal. The country confi guration may disable this command. The modem returns an
ERROR result if this command is issued.
&HT0-9 EMMF tone for digit n where the command was &HTn.
&HT10 EMMF tone”*”
&HT11 EMMF tone “#”
&HT12 EMMF tone “A”
&HT13 EMMF tone “B”
&HT14 EMMF tone “C”
&HT15 EMMF tone “D”
&HT16 V.21 channel 1 mark
&HT17 V.21 channel 2 marks
&HT18 V.23 1200bps marks
&HT19 V.23 75bps marks
&HT20 V.21 channel 1 spaces
&HT21 V.21 channel 2 spaces
&HT22 V.23 1200bps spaces
&HT23 V.23 75bps spaces
&HT24 V.22 originate mode
&HT25 V.22 answer mode
&HT26 V.22bis originate mode
&HT27 V.22bis answer mode
&HT28 V.25 calling tone
&HT29 550Hz guard tone
&HT30 1800Hz guard tone
&HT31 Silence
I Identifi cation The I command asks the modem for information that can be used to determine the modem’s compatibility with other
software and to ensure the modem is operating properly.
I0 Display product code. The modem reports its product code to the terminal. The modem produces
information text dependent upon its features and capabilities.
I1 Display ROM checksum. The modem reports the value of its ROM checksum. The decimal number
displayed is the eight bit sum (from 0 to 255) of all the bytes in ROM.
I2 Test the ROM checksum. The modem checks its ROM to ensure it is correct. The modem reports a
result code indicating whether the ROM is OK or in ERROR.
I3 Display Software Versions. The modem reports the modem controller and data pump software
versions, and the modem controller software release date, to the terminal.
I4 Display Modem Identifi cation. The modem reports a confi gurable identifi cation message to the
terminal.
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AT Command Set
Command Function and Description
M Speaker On/Off
Options
The country confi guration may disable the speaker. If so, this command will return an ERROR result.
M0 Speaker always off.
M1 Speaker on until carrier detected. This is the default value in North America.
M2 Speaker always on; stays on after carrier is detected.
M3 Speaker off as digits are dialed, but on during ringback and on until carrier signal is detected.
O Return to On-Line
Mode
This command returns the modem to the on-line mode. It is frequently used after th escape character sequence
(+++) to resume communication with the remote modem. If handshaking is started, the modem uses Originate or
Answer mode handshaking depending upon whether the modem originated or answered the telephone call.
O0 Return the modem to the On-Line state from the Command state during a telephone line connection.
The modem starts handshaking if there was no telephone line connection but the modem was off
hook.
O1 Return the modem to the On-Line state and retrain its data pump during a telephone line connection.
The modem starts handshaking if there was no telephone line connection but the modem was off
hook.
&P Pulse Dial Make/
Break Ratios
Sets cadence of pulse dial. The country confi guration may disable this command, forcing particular pulse dialing
parameters. In this event, the modem returns an ERROR result if this command is issued.
&P0 39%/61% make/break ratio and 10 pulses per second when pulse dialing. This is the default value.
&P1 33%/67% make/break ratio and 10 pulses per second when pulse dialing.
&P2 39%/61% make/break ratio and 20 pulses per second when pulse dialing.
&P3 33%/67% make/break ratio and 20 pulses per second when pulse dialing
Q Result Code
Display Options
This command allows the user to either display result codes or to not display result codes.
Q0 Result codes will be displayed. This is the default value for North America.
Q1 Result codes will not be displayed.
Sn Set the current
S-register to n
This command sets the current S-register to the value “n” selected by the user. For example, ATS7 will set the current
S-register to S7. Default value is 0. Sn addresses a particular S-register number so future commands like ? and = will
read of write the S-register. Modem reset and the &F command select S0 as the default S-register.
? Read an
S-Register
This command displays the value of the last S-register named in the Sn command.
=x Write an
S-Register
This command writes the value x to the last S-register named in the Sn command. The range of valid values for x
depends upon which S-register is being written. 0 is assumed if no value is given for x.
T Tone Dialing Selects the tone method of dialing.
V Result Code
Format
This command changes the format in which result codes are displayed.
V0 All result codes will be displayed as numbers.
V1 All result codes will be displayed as words (verbose form). This is the default value for North America.
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CPC2400E
AT Command Set
Command Function and Description
X Call Progress The X command controls whether or not a busy signal or dial tone should be detected when dialing. The X command
also limits the result codes the modem may return when dialing. The operation of the X command is confi gurable for
operation in different countries.
X0 Neither busy signal nor dial tone are detected. When a telephone line connection is made the result
code does not indicate the telephone line data rate.
X1 Neither busy signal nor dial tone are detected. When a telephone line connection is made the result
code indicates the telephone line data rate.
X2 Busy signal is not detected. Dial tone is detected. When a telephone line connection is made the result
code indicates the telephone line data rate.
X3 Busy signal is detected. Dial tone is not detected. When a telephone line connection is made the result
code indicates the telephone line data rate.
X4 Both busy signal and dial tone are detected. When a telephone line connection is made the result
code indicates the telephone line data rate. This is the default value in North America.
The @ and W dial modifi ers are not affected by the X command. The @ dial modifi er may return the result codes 8
(NO ANSWER) or 7 (BUSY) each time it appears in the dial string. The W dial modifi er may return the result codes 6
(NO DIALTONE) or 7 (BUSY) each time it appears in the dial string.
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Dial Modifiers
Modifi er Function
0-9 A B C D # * Dialing digits and characters. The digits and characters 0-9 A B C D # * specify what numbers the modem dials.
The characters A B C D # * work only when tone dialing is used, they are ignored when pulse dialing is used. The
characters A, B, C, and D may be disabled in countries prohibiting their use.
P Pulse dialing. P selects the pulse method of dialing. P can be issued within a dial command or as a separate
command. The default method of dialing is Pulse.
R Originate a Call in Answer Mode. R makes the modem handshake in answer mode so it can originate a call to an
originate-only modem.
T Tone dialing. T selects the tone method of dialing. T can be issued within a dial command or as a separate command.
The default method of dialing is Pulse.
W Wait for dial tone. W makes the modem wait for a dial tone before proceeding. If no dial tone is detected the modem
hangs up the telephone line and returns the NO DIALTONE result code.
, Delay Processing of Next Character. A comma (,) makes the modem pause for the length of time in Sregister S8
before processing the next character in a dial string.
@ Wait for Quiet Answer. @ makes the modem listen for 5 seconds of silence before continuing. The modem will wait
up to the length of time in S-register S7. If 5 seconds (confi gurable by country) of silence are not detected within the
time period in S-register S7, the modem hangs up and returns the NO ANSWER result code. If 5 seconds of silence
are detected, the modem continues processing the other characters in the dial string.
! Timed Break Recall (Hookfl ash). A ! makes the modem hang up the telephone line for the length of time in S-register
S29, then take the telephone line off hook again. This is frequently used to access a PBX’s call transfer function.
; Return to Command State after dialing. A semicolon (;) tells the modem to return to command state after dialing
without breaking the telephone line connection and without handshaking with the other modem. The semicolon may
only be used when calling a voice mail system that permits tones to transmit numbers once a connection has been
established.
Dial modifiers perform special functions within a dial
command. For example,
ATDT9W1552368!@#71234;<CR>
instructs the modem to use tone dialing (T), to access
a number outside a PBX (9), to wait for dial tone (W),
to dial the number 1552368, to do a hook-flash (i.e.
timed break recall), to wait for quiet answer, and to
issue the PBX transfer code #7 before dialing
extension number 1234, then to return to the
Command state before initiating the handshake.
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CPC2400E
Modem S-Registers
Command Range Units Description
S0 0 - 255 Rings Set number of rings to auto-answer. The country confi guration may disable the modem’s ability
to detect a telephone line ring signal. In this case the modem will never automatically answer the
telephone regardless of the S0 setting. Default = 0 (auto-answer disabled)
S1 0 - 255 Rings Returns the number of times the phone rings. Default = 0
S2 0 - 255 ASCII Set Escape Sequence Character. Setting S2 to a value greater than 127 disables the character
escape sequence, preventing the modem from returning to Command state when in the On-Line state.
Default = 43
S3 0 - 127 ASCII Set the End of Line character. Default = 13
S4 0 - 127 ASCII Set the Line Feed Character. Default = 10
S5 0 - 127 ASCII Set the BackSpace Character. Default = 8
S6 2 - 255 Seconds Delay to Wait Before Performing a Blind Dial. Default = 2 seconds
S7 1 - 255 Seconds Delay to Wait for Carrier after dialing. Default = 30 seconds
S8 0 - 255 Seconds Delay to Wait when a Comma Dial Modifi er is Processed. Default = 2 sec.
S9 1 - 255 1/10th sec Time Carrier Must be Present Before Being Recognized. Default = 0.6 sec.
S10 1 - 255 1/10th sec Delay Between Lost Carrier and Hang Up. Setting S-register S10 to 255 makes the modem never
hang up the telephone line because of a loss of carrier. Default = 14 tenths of a second
S11 50 - 255 msec Multi-Frequency Tone duration. Default = 95 milliseconds
S12 0 - 255 1/50th sec Escape Prompt delay time. This is the prompt delay time for escape sequences from the On-Line state
to the Command state. Default = 50 fi ftieths of a second
S13 Reserved Reserved Reserved
S14 Reserved Reserved Reserved
S15 Reserved Reserved Reserved
S16 Reserved Reserved Reserved
S17 -6 to -43 - dBm Set Transmit level. Default = -10 dBm
S18 Reserved Reserved Reserved
S19 Reserved Reserved Reserved
S20 Reserved Reserved Reserved
The value of an S-register is modified by ATSn =x,
where n is the register number and x is the value to be
stored in that particular register. Each S-register has
three values that may be configured for different
countries: a default value, an upper limit and a lower
limit. The values shown in this manual are for North
America.
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Command Range Units Description
S21 Reserved Reserved Reserved
S22 Reserved Reserved Reserved
S23 Reserved Reserved Reserved
S24 Reserved Reserved Reserved
S25 0 - 255 Seconds or
1/100th sec
During synchronous operation with the &Q1 command in effect, S-register S25 is the number of
seconds after a telephone line connection is made before the modem examines DTR. This allows
suffi cient time to disconnect the modem from an asynchronous terminal and attach it to a synchronous
terminal. In the On-Line or Command state during any mode of operation, changes in DTR for less
than S25 hundredths of a second are ignored.
S26 Reserved Reserved Reserved
S27 Reserved Reserved Reserved
S28 0 - 255 Minutes Terminal inactivity timeout. Hangs up the modem after S28 minutes if no characters are received from
the modem’s terminal. Default = 0
S29 0 - 255 1/50th sec Hook Flash On-Hook time. The amount of time in 20 millisecond units the modem will leave the
telephone on-hook while performing a hook-fl ash according to the “!” dial string modifi er. Default = 25
fi ftieths of a second.
S37 0 - 6 Code Set Highest Line Rate - determines the highest telephone line data rate the modem will use when
connecting with a remote modem. See “Setting the Highest Line Rate” section below. Default = 0.
S-37 Value Carrier Data Rate
0 The data rate of the last AT command
4 Reserved
5 V.22, Bell 212A 1200 bps. See the B command
6 V.22bis 2400 bps
The connect rate can be selected by S-register S37. The following connect rates are supported.
Setting the Highest Line Rate
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16 R03
CPC2400E
Number Word Result Code Description
0 OK Command Line Executed without errors
1 CONNECT The modem is in the On-line state, ready to transfer data.
2 RING The modem has detected a ring signal on the telephone line. The country confi guration may disable the
modem’s ability to detect a telephone line ring signal.
3 NO CARRIER No carrier signal was detected when answering or placing a telephone call, or carrier was lost during a
call. The modem also returns this response message when the telephone line connection is broken for any
reason.
4 ERROR An invalid command was issued, or there was an error at any place in the command line.
5 CONNECT 1200 The modem is in the On-line state, ready to transfer data.
6 NO DIALTONE No dial tone was detected when the modem took the telephone line off hook.
7 BUSY The modem detected a busy signal on the telephone line.
8 NO ANSWER Not enough silence was detected when the @ dial modifi er was used.
10 CONNECT 2400 The modem is in the On-line state, ready to transfer data. The telephone line data rate is 2400bps.
16 CONNECT 1200/75 The modem is in the On-Line state, ready to transfer data. This modem transmits at 1200 bps and
receives at 75 bps.
17 CONNECT 75/1200 The modem is in the On-Line state, ready to transfer data. This modemtransmits at 75bps and receives at
1200 bps.
20 BLACKLISTED The modem will not allow any number to be dialed until after the modem is reset.
21 DELAYED The modem will not allow any number to be dialed now, but will allow dialing at some future time.
Dial Modifiers
A result code is a line of text or a number the modem
sends to the terminal to indicate the result of a
command execution. Some CONNECT result codes
indicate the telephone line data rate. The following
table provides a list of the available result codes.
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IXYS Integrated Circuits Division makes no representations or warranties with respect to the accuracy or completeness of the contents of this publication and reserves the right to make
changes to specifications and product descriptions at any time without notice. Neither circuit patent licenses nor indemnity are expressed or implied. Except as set forth in IXYS Integrated
Circuits Division’s Standard Terms and Conditions of Sale, IXYS Integrated Circuits Division assumes no liability whatsoever, and disclaims any express or implied warranty, relating to
its products including, but not limited to, the implied warranty of merchantability, fitness for a particular purpose, or infringement of any intellectual property right.
The products described in this document are not designed, intended, authorized or warranted for use as components in systems intended for surgical implant into the body, or in other
applications intended to support or sustain life, or where malfunction of IXYS Integrated Circuits Division’s product may result in direct physical harm, injury, or death to a person or severe
property or environmental damage. IXYS Integrated Circuits Division reserves the right to discontinue or make changes to its products at any time without notice.
Specification: DS-CPC2400E-R03
©Copyright 2012, IXYS Integrated Circuits Division
OptoMOS® is a registered trademark of IXYS Integrated Circuits Division
All rights reserved. Printed in USA.
12/22/2012
For additional information please visit our website at: www.ixysic.com
17
CPC2400E
An escape sequence is one or more particular
characters sent from the terminal to the modem during
the On-Line state. This is done to switch the modem
to the command state so modem commands may
be entered during a telephone line connection. The
Escape Sequence characters are typically sent to the
other modems as data.
An escape sequence should not occur accidentally
during an exchange of data between two modems.
Unfortunately, it is impossible to guarantee any escape
sequence will never occur naturally since there are no
restrictions on the data or timing between characters
sent between two modems during the On-Line state.
The only method of switching form the On-Line state
to the Command state that does not ever occur
naturally during an exchange of data is the Data
Terminal Ready signal (the &D1 command). The
terminal has complete control of this signal and it is
not part of the data exchanged between the modems.
The Hayes escape sequence was adopted by many
modem manufacturers and communication programs
before Hayes was granted a patent for the escape
sequence guard times. Now the unpatented Time
Independent Escape Sequence (TIES) has gained
popularity with many modem manufacturers.
Then:
a. If one of the recognized AT commands is received
before the timer expires, the timer is stopped, the
command is executed and its result code is sent to
the terminal.
b. If any other data is received while the timer is
running, the timer is stopped, the modem returns to
the On-Line state and the received data is sent to the
other modem.
c. If the timer expires, a confirming result code is
sent to the terminal, indicating the modem is in
the Command state. The escape character can be
changed through S-Register S2. The prompt delay
timer can be changed (in 1/50 second increments)
through S-Register S12 (see S-Registers section).
Escape Sequences
TIES Escape Sequence
TIES stands for Time Independent Escape Sequence.
TIES was developed by a number of modem
manufacturers in response to Hayes enforcing patent
rights for their escape sequence guard time patent.
The Time Independent Escape Sequence is a
sequence of 3 escape characters (+ characters by
default). Once these characters have been recognized,
the modem enters the Command state without
sending a confirming result code to the terminal and
the modem starts a prompt delay timer.
Carrier Detection
After handshaking, the modem determines if a
telephone line connection exists by detecting the
carrier signal from the other modem. If the carrier is
not detected for a long enough period of time, the
modem assumes the telephone line connection with
the other modem has been broken. The modem uses
S-register S9 to determine how long a carrier must
be present before it is “detected.” The modem uses
S-register S10 to determine how long a carrier may
not be detected before the telephone line is hung up.
