ETC CH2056TBR

HIGH SPEED Modem and FAX FAMILY
CH2056/TBR/ETBR
CH1799/TBR/ETBR
CH1794
–
–
–
V.90 / 57,600bps/TBR21
V.34bis / 33,600bps/TBR21
V.32bis / 14,400bps
The HS Modem family is pin compatible with
Cermetek’s low cost CH1786 V.22bis, 2400bps
modem family. Each module in the HS Modem family
is a self-contained modem and is FCC Part 68
approved
and
Canadian
DOT
approvable.
Additionally, the CH1799TBR/ETBR and the
CH2056TBR/ETBR products meet the European
TBR21 requirements.
FEATURES
•
Supports V.90, V.34bis, V.34, V.32bis, V.32,
V.22bis, V.22A/B, V.23, V.21, Bell 212A and 103.
•
CH2056 supports V.80 Synchronous operation.
•
Error correcting: V.42 LAMP, MNP 2-4 and
MNP10.
•
Data Compression: V.42bis and MNP 5
•
MNP10 Data through put enhancement for cellular
operation.
•
DTE serial interface with speeds up to 230.4kbps
(CH2056), 115.2 (CH1799) or 57.6kbps (CH1794).
•
Automatic baud rate adaptability utilizing speed
sensing, flow control and data buffers.
•
Send & Receive FAX class 1, Group 3 supported.
•
Serial V.24, 5 volt interface.
•
NVRAM directory and stored profiles.
•
AT Command structure, with extensions.
•
Built-in DAA with 1500 VAC RMS isolation 2122V
peak surge protection.
•
UL 1950 and CSA C22.2 950 Recognized
(E104957).
•
Leased Line version available CH1799LL
•
FCC part 68 Approved/DOT CSA CS-03 Part I
Approvable.
•
+5 Volt operation with zero power option
•
Small size: 1.35” x 1.38” x 0.61” (nominal, 0.55”
upon request).
•
Pin compatible with low speed/low cost CH1786
•
TBR21
compliant
versions
available:
CH1799TBR/ETBR and CH2056TBR/ETBR.
These ultra small modules are designed for PCB
through-hole mounting and are 1.35” x 1.38” x 0.61”
(nominal, 0.55” upon request) in size. The HS Modem
family requires only two external interfaces: a CCITT
V.24 serial interface for direct access to a UART, and
a Tip and Ring RJ-11C Jack for the PSTN line
connection. The HS Modem can be controlled with
industry standard AT commands and is compatible
with available industry communication software.
DESCRIPTION OF FUNCTIONAL BLOCKS
AND DISCUSSION OF BASIC OPERATIONS
Figure 1 contains a functional block drawing of the HS
Modem family of products. Each HS Modem product
consists
of
a
serial
interface
buffer,
modulator/demodulator, modem controller with error
correction and data compression, non-volatile RAM
and a DAA.
INTRODUCTION
The CH2056, CH1799 and CH1794 (HS Modem
Family) are industrial grade high-speed modem
modules. Each HS Modem product supports a range
of modem standards and speeds from 300bps to
14,400bps, 28,800bps, 33,600bps or 57,600bps. By
using built in compression algorithms the operation
speed can be expanded to the maximum DTE rate of
57.6kbps for the CH1794, 115.2kbps for the CH1799
and 230.4kbps for the CH2056. A choice of error
correcting schemes is available including MNP 10 for
cellular telephone applications. The HS Modem family
supports Send and Receive FAX. The CH1799LL
operates exclusively on non-voltage bearing leased
line.
2003 Cermetek Microelectronics, Inc.
Figure 1. Functional Block Diagram of HS Modem
Family.
Serial Host Interface Buffer. The HS Modem utilizes
a serial V.24 EIA 232-E 5V interface to control the
modem. The HS Modem products can communicate
over the serial interface with the Data Terminal
Page 1
Document No. 607-0003 Revision K3 (09/03)
Cermetek Microelectronics, Inc.
High Speed Modem and FAX Family
Equipment (DTE) at a fixed speed regardless of the
carrier line modulation speed (DCE) of the PSTN
modem connection. This eliminates the need to have
the DTE step up or step down in speed based on the
in-coming or out-going PSTN communication data
rate. Hence, the DTE can train the CH2056, to say
56kbps, and talk to a slower in-coming data
connection at say, 2400bps without changing host
speed. Conversely, the host DTE trained at 14.4kbps
can also communicate with the modems at higher
speeds, say 28.8kbps. This is accomplished by
invoking internal automatic data flow control. The HS
Modem family has a resident buffer to allow for this
auto baud operation.
Non-Volatile RAM (NVRAM). NVRAM can store
user-customized configurations.
The AT&Wn
command will store the active modem configuration in
one of two NVRAM locations as selected by an n of 0
or 1. The AT&Yn command selects one of the stored
modem configurations to be automatically recalled and
made active upon reset or power up. The ATZn
command immediately recalls and activates a stored
configuration. See Tables 7A and 7B for storable SRegisters and Commands.
The NVRAM can save up to four telephone numbers,
with up to 31 digits or modifiers in each telephone
number. The AT&Zn=s command will store s, the
telephone number dial string. The ATDS=n command
will cause the modem to dial one of the four stored
telephone numbers. The NVRAM storage location for
the four telephone numbers is selected by an n of 0, 1,
2, or 3.
Telephone Line Interface or DAA. High performance
modems are extremely sensitive to DAA (Data Access
Arrangement) performance. The difference between a
good modem and a fair one is in the DAA
performance. The HS Modem family includes a
unique low distortion DAA designed for optimal
performance over all PSTN line conditions thereby
achieving the most reliable and best performance
PSTN connections.
The HS Modem family is designed to meet North
American telephone standards as set by the FCC Part
68 (USA) and CSA CS-03 Part I (Canada). Among the
more critical parameters, the PSTN line interface is
designed to meet 1500 VAC RMS isolation and
provide 2122V peak surge protection. Consequently,
the HS Modem family of products satisfies U.S. and
Canadian requirements, and will meet other
international approval agency requirements that
specify these levels of isolation. The TBR/ETBR
variants also meet the European TBR21 requirements.
Pins 1 and 2 function as both input and output
connections to the PSTN. To maximize field reliability
in hostile environments, for Canadian approval, for UL
2003 Cermetek Microelectronics, Inc.
Page 2
compliance, and also optionally for FCC Part 15
compliance, these two pins must be routed through an
external network such as that briefly described in
Figure 6A and described in more detail in Cermetek
Application Note # 126.
Each HS Modem product comes with FCC Part 68
approval and is shipped from the factory with an FCC
Label indicating registration number and ringer
equivalent. This label should be prominently displayed
on the end product. With the exception of the U.S.,
most countries (including Canada) require submission
of the final product or system containing the HS
Modem to the appropriate governing regulatory
agency for approval. Typically this is accomplished by
submitting the final end product to an independent test
house or consultant for evaluation.
The test
house/consultant then forwards the test results and
applicable documents to the regulatory agency.
Contact Cermetek for a list of suggested consultants.
Modulation/Demodulation/Error Correcting and
Data Compression. These functions are provided by
an industry standard modem chip set which has been
adapted for use with the HS Modem family. The
Modulation/Demodulation scheme supports the
industry modem standards listed below.
SUPPORTED MODULATION STANDARDS
Bell 103
CCITT V.22
Bell212A
CCITT V.22bis
CCITT V.32
CCITT V.32bis
CCITT V.34
CCITT V.34bis
CCITT V.90
The HS Modem supports V.42 LAMP, MNP 2-4, MNP
10 error correcting protocols. The CH1794 uses
MNP5 data compression techniques and the
CH1799/CH2056 uses V.42bis data compression,
allowing data transmission rates of up to a maximum
of
57.6kbps/115.2kbps/230.4kbps,
respectively.
These high DTE data rates are supported by the HS
Modem serial interface via its auto baud capability.
Note that the maximum speed attained is limited by
the maximum speed available from the DTE.
The resident Modulator/Demodulator supports line
equalization and forward error correction.
IMPORTANT NOTE
The V.90 standard prescribes 56kbps
downlink and 33.6kbps uplink. Consequently,
two V.90 modems connected back-to-back will
send at 33.6kbps.
Document No. 607-0003 Revision K3 (09/03)
Cermetek Microelectronics, Inc.
High Speed Modem and FAX Family
CONNECTING TO THE HOST UART
Since a modem communicates data serially and most
host products handle data in a parallel format, a UART
is needed to make parallel-to-serial and serial-toparallel translations.
SUPPORTED FEATURES
Modem is powered down. The internal blocking diode
provides supply isolation.
The pins of the HS Modem will be in an undefined
state when powered is switched off. This must be
taken into consideration to assure that no unwanted
signals are presented to the HS Modem during power
down.
AT Command Set. The HS Modem supports the AT
Command set with extensions and can operate with
industry standard communication software. The AT
Commands are compatible with TR302.2/88-08006.
Serial Host Interface.
The HS Modem family
operates in asynchronous mode and supports a 5V,
RS232- like interface called V.24 (EIA-232-E). The HS
Modem supports a full RS-232C/V.24 serial interface.
Signal levels are TTL rather than RS-232C level
compatible, which allows direct connection of the HS
Modem to the host’s UART without level translating
circuitry. See Table 3 for a complete set of pin
descriptions.
The modem is controlled by sending serial commands
over TXD and by monitoring serial status messages
returned on RXD. All other serial interface lines may
be utilized for the convenience of a particular
application but are not required by the modem.
Unused outputs from the HS Modem should be left
unconnected. Unused inputs should be tied to the
proper logic level. See Table 3.
Speaker Interface. The SPK output reflects the
receiver analog input and provides a signal that can be
used to monitor call progress. The SPK signal can
drive a 300-ohm load directly. Typically, the SPK
signal is input into an audio power amplifier and the
amplifier, in turn, drives the speaker coil. The speaker
is activated with the ATM command. The speaker
volume is adjusted using the ATLn command; where n
is 0, 1, 2, or 3. Increasing numbers correspond to
higher volume. Figure 3 indicates one method of
driving an external 8-ohm speaker.
Zero Power Mode. If an application calls for zero
power during standby periods, the power may be
switched off using external circuitry and then reapplied
when the HS Modem’s RI pin becomes active. The
HS Modem can thus be powered down to zero.
Referring to Figure 2, the controller activates the relay
switch, supplying power (+5V) to the HS Modem. In
this configuration, the ring signal is used to “wake up”
the HS Modem when the HS Modem is in the power
down state.
The internal structure of the RI pin consists of an open
collector opto transistor with a 30k ohm pull-up through
a blocking diode to 5V. The user should apply his own
pull-up resistor to an active 5V source when the HS
2003 Cermetek Microelectronics, Inc.
Page 3
Figure 2. Zero Power Operation.
Power Supply. The HS Modem module is a complex
set of sensitive subsystems. During the course of
normal operation, the HS Modem decodes analog
signals from the telephone line that are in the millivolt
range. Steps must be taken by the user to guarantee
that power supply noise on all supply lines, including
ground, does not exceed 25mV peak to peak. If
necessary, use dedicated power and ground planes.
Failure to provide such operating conditions could
cause the HS Modem to malfunction or to function
erratically.
The HS Modem family requires +5V ±5% supply. It is
recommended that bypass capacitors be placed on the
power supply as close to the HS Modem’s supply input
pins as practical. It is recommended that a 10 µF or
greater tantalum capacitor in parallel with a 0.1 µF
ceramic capacitor be used. The user must also
provide shielding from nearby sources of EMI, such as
relays, motors and other power supplies.
Automatic Speed/Format Sensing. The HS Modem
supports both Command and Data modes of
operation.
The HS Modem can automatically determine the
speed and format of the data sent from the DTE over
the serial interface; and can sense the following broad
range of speeds:
Document No. 607-0003 Revision K3 (09/03)
Cermetek Microelectronics, Inc.
CH1794
CH1799
CH2056
High Speed Modem and FAX Family
300, 600, 1200, 2400, 4800, 7200,
9600, 12000, 14400, 19200, 38400, and
57600bps.
300, 600, 1200, 2400, 4800, 7200,
9600, 12000, 14400, 16800, 19200,
21600, 24000, 26400, 28800, 38400,
57600, and 115200bps.
300, 600, 1200, 2400, 4800, 7200,
9600, 12000, 14400, 16800, 19200,
21600, 24000, 26400, 28800, 38400,
57600, 115200, and 230400bps.
for an alternative voice/tone implementation that
utilizes dual supply operational amplifiers.
Table 2. HS Modem Auto Configuration Based on
DTE Configuration.
DTE Configuration
HS Modem
Configuration
7 mark
7 none
7 space
8 none
8 mark
8 none
8 space
8 even
The data formats in Table 1 are recognized by the HS
Modem family of products.
Table 1. Data Formats Recognized by HS Modem
Family.
No. of
Character
Data Length
Stop
Length
Parity (No. of Bits)
Bits
(No. of Bits)
None
7
2
10
Odd
7
1
10
Even
7
1
10
None
8
1
10
Odd
8
1
11*
Even
8
1
11*
*11 bit characters are sensed, but the parity bits are
stripped off during data transmission in Normal and
Error Correction modes.
The HS Modem can sense data with mark or space
parity and configures itself as described in Table 2.
The HS Modem is trained to a selected speed with an
AT<CR> training sequence. Thus, the DTE to modem
serial interface speed can be set independent of the
DCE or line carrier connecting speed (with minor
restrictions, see the AT+ MS command). This allows
greater flexibility when selecting DCE line carrier
modulation speed thereby affording the user with
optimum data throughput performance. To maximize
effective modem data throughput speed, the DTE to
modem serial interface speed should be set to the
highest speed available without invoking the use of the
HS Modem’s built-in flow control. Although flow
control facilitates communication with higher speed
modes by the DTE, use of flow control causes an
overall throughput data rate penalty.
Voice/Tone Injection Port. The HS Modem Family
provides pin T1 to allow the user to share the PSTN
line interface associated with the modem for voice and
DTMF applications. Figure 5 contains a schematic
which uses a 5 Volt single supply operational amplifier
and indicates one possible configuration for voice/tone
utilization.
Refer to Cermetek Application Note #170, 2-4 Wire
Converter for Use with CH179X and CH2056 Modems,
2003 Cermetek Microelectronics, Inc.
Page 4
Figure 3. Speaker Control Circuit.
All HS Modem products are designed with pin T1
coupled directly to the internal DAA. When using the
HS Modem in data mode, T1 should float and be
disconnected from any potential signal because any
signal on T1 during data operation will affect the HS
Modem’s output. If T1 is being asserted from another
application, use a relay or zero impedance switch to
disconnect T1 when in data mode.
When voice and data are both being used, and the T1
pin is active, it is typical for voice communication to
precede data communication.
In this case, the
following commands should be used to configure the
HS Modem to allow for full utilization of the Voice/Tone
injection feature. These commands disable autoanswer and eliminate hang-up due to lack of carrier
signal.
1. Enter: ATS0=0<CR>
2. Enter: ATS7=255<CR>
3. Enter: ATS10=255<CR>
The following
implementation
applications.
command sequences illustrate
of
common
voice/tone
port
1. To answer a voice call:
(a) Enter: ATH1<CR>
(b) Switch local voice source into T1
(c) Begin Voice Conversation
Document No. 607-0003 Revision K3 (09/03)
Cermetek Microelectronics, Inc.
High Speed Modem and FAX Family
3. To disconnect (hang-up) a voice call or data call:
(a) Return to control mode by entering: +++
(b) Enter: ATH<CR>
The escape sequence consists of a “guard time” (a
period where no characters are sent to the modem),
followed by 3 escape characters, followed by a second
guard time. At power-up, the guard time is set to 1
second, and the escape character is set as ”+.” Note
that a 50 msec delay is required between escape
characters. These two parameters can be modified
via registers S2 and S12, respectively.
4. To place a voice call using the HS Modem DTMF
facilities:
(a) Enter: ATDT1234567<CR>
Where 1234567 is the phone number
(b) Then switch to local voice source
The HS modem will stay off-hook with its carrier on
after the escape sequence is received. The HS
Modem will return an OK status message when it is
ready to accept commands. To put the HS Modem
back into data mode, issue command ATO<CR>.
MODEM CONTROL
THE COMMAND FORMAT
The HS Modem may be controlled by sending serial
ASCII command sequences. The commands are sent
to the modem serially on the TXD pin. After execution
of a received command, the modem returns a serial
status message that completion status. Refer to Table
5A, 5B and 5C for a complete list of status messages.
HS Modem commands consist of three elements:
1. The attention sequence,
2. The commands themselves and
3. A terminating carriage return.
2. To switch to data mode, switch local voice source
from T1:
(a) At the Originate Modem, enter: ATX1<CR>
(b) At the Answer Modem, enter: ATA<CR>
Enter:
Result:
ATDT1234567<CR>
Modem goes off-hook and tone dials phone
number 1234567.
MODEM STATES
The HS Modem can be in either command mode or
data mode. When the modem is idle, it is in command
mode by default and will recognize commands. When
data transmission is in progress, the HS modem is in
the data mode state and will not recognize commands.
To force the HS Modem to recognize commands, the
host must send an “escape sequence” to the HS
Modem forcing it out of data mode and into command
mode.
WARNING
The HS Modem family of products has been FCC
Part 68 approved as data/FAX modems. Utilization
of the Voice/Tone Port requires further registration.
The FCC requires that the entire system, including
the HS Modem and the handset or DTMF
transceiver, adhere to Part 68 rules.
TIP
ANALOG VOICE
INJECTED SIGNALS
RJ-11
JACK
RING
T1
SPK
HS MODEM
FAMILY
RXD
V.24
EIA-232-E
INTERFACE
OR
UART
SPEAKER
CONTROL
NOTE: SPEAKER CONTROL AND PHONE
CONTROL ARE ANCILLARY CIRCUITS
SHOWN ELSEWHERE IN THIS DATA SHEET.
DCD
DSR
RI
CTS
*SIGNAL GND MUST BE CONNECTED TO
EARTH GROUND
TXD
DTR
Vcc
3
2
RI
EXTERNAL RESET
+
-
8
Vcc
22K
1
LM393
4
RST
10K
5
6
+5V
.1uF
GND
Figure 4.
10K
4.7K
LM393
4.7uF
+
7
Isolated
Envelope
Ring Detect
HS Modem Family Application Diagram.
2003 Cermetek Microelectronics, Inc.
Page 5
Document No. 607-0003 Revision K3 (09/03)
Cermetek Microelectronics, Inc.
High Speed Modem and FAX Family
AT [Commands]<CR>.
Where: AT represents attention sequence. A and T
may be either upper or lower case but must be
the same case.
[Command] represents
command strings.
Where: <CR> represents carriage return (ASCII 13 or
HEX 0D)
<LF> represents line feed (ASCII 10 or HEX
0A)
The HS Modem will respond with one of the following
status messages depending on whether it is optioned
for abbreviated (terse) or English (verbose) status
messages.
HS Modem Reset. Upon applying power to the HS
Modem, the HS Modem automatically generates an
internal reset pulse. The user can also reset the
modem externally by applying a high-going reset pulse
to the RST pin for at least 10 msec after the +5V
power supply has stabilized.
Delay sending
commands to the HS Mode for 2 seconds after reset
has been initiated to allow the HS Modem time to
properly reconfigure.
On power up, or when reset is initiated either by the
ATZ<CR> command or by the RST pin, the modem
will reconfigure to its default state with the line carrier
modulation speed set to:
1. 14.4kbps for the CH1794
2. 33.6kbps for the CH1799
3. 57.6kbps for the CH2056
Result: 0 <CR> (Terse)
or
Result: <CR><LF>
OK
<CR><LF> (Verbose)
After accepting the AT<CR> command the HS modem
is in idle mode and is ready to accept additional
commands.
An alternate attention sequence A/ may be issued
which behaves much like the AT sequence except that
it causes the last entered command specified with an
AT prefix to be executed. When given, it must be in
upper case ASCII. No carriage return is needed for
this command.
When entering commands to the modem, the
backspace character-control-H (ASCII 8 or HEX 08)
can be used to edit mistakes. AT and A/ may not be
edited however. Multiple commands may be placed
on a command line. A command line may be as long
as 40 characters, excluding the letters AT. By way of
example, the command below instructs the HS Modem
to configure itself to not echo characters when in
command mode (E0) and then puts itself in answer
mode (A).
Enter: ATE0A<CR>
Result: OK<CR><LF>
AT Command Set. The available command set is
divided into four types of commands: dial modifiers,
basic commands, ampersand and percent commands.
Refer to the complete list in Tables 6A and 6B.
INITIALIZING THE MODEM
Before commands may be sent to the HS Modem, the
modem must be initialized. This is a two step process:
Step 1. Modem Reset.
This is accomplished by
applying a hardware-reset pulse to pin RST or
by switching the power off then back on.
2003 Cermetek Microelectronics, Inc.
Step 2. Initial Modem Training. The modem must be
trained to the host DTE speed and parity (odd,
even, mark, space or none). These activities
are briefly described below.
Page 6
If desired, any speed, error correction, or data
compression method available on the HS Modem can
be locked in, using the ATNn and/or AT+MS
commands.
Training the Modem. Each modem must be trained
to match the host DTE speed and parity so that it is
able to recognize serial asynchronous commands sent
to it by the DTE.
The DTE must retrain the modem each time a reset
pulse is applied on RST or after a RESET serial
command has been issued.
STATUS MESSAGES AND RESULTS CODES
A result code is issued by the HS Modem to the DTE
for all commands executed by the HS Modem except
dialing commands. Further, various activities on the
PSTN are also signaled to the DTE by the HS Modem.
All result codes have either a terse, short form version
(which is identified by a number followed by a <CR>)
or a verbose long form English-like message version
(which is preceded and terminated with a <CR> and
<LF>).
The user may suppress certain subsets of the nonextended result codes. This is accomplished by
selecting subsets of the result code set using the
ATXn command, where n=0, 1, 2 or 3. Optionally, the
user may specify an extended set of results codes
(codes above 35) by setting Register S95. See the
detailed description of results codes in Table 5A, 5B
and 5C.
All AT commands, other than dialing commands, will
be responded to with either an OK (short form result
Document No. 607-0003 Revision K3 (09/03)
Cermetek Microelectronics, Inc.
High Speed Modem and FAX Family
code 0) or the command is valid or accepted, or with
an ERROR (result code 4) if the command is not
recognized. The detail contained in the error result
codes signaled to the DTE depends on the level of
message suppression employed by the user. As can
be seen from Tables 5A, 5B and 5C, specifying X4
allows the HS Modem to utilize the entire range of
non-extended messages, whereas X0 suppresses all
but the very basic result codes. Most of the result
codes allowed under X1, X2 and X3 are considered
call progress status codes and, in practice, are
suppressed except for the case of debugging
activities. It is recommended that the non-extended
result codes be used in all cases.
It should be noted that the default connect result codes
9-20 indicate DTE connection speed, not Carrier Line
DCE speed. Hence, a CH1794 will connect at a
maximum speed of 19.2kbps (result code 16). The
CH1799 will connect at a maximum DTE speed of
38.4kbps (result code of 17) and the CH2056 will
connect at a maximum speed of 57.6kbps (result code
18) unless the DTE is forced to a higher speed by
selection of data compression. In this case, the
maximum DTE to modem speed is 230.4kbps (result
code20).
Extensions to the basic result code set may be
specified by Register S95, which allows for the use of
result codes 40-64, 165-194.
IMPORTANT NOTE
Result codes 53-64 are supported by the CH1799
and CH2056. Result codes 165-194 are only
supported by the CH2056. To obtain a detailed
status report for a given modem communication
configuration, use the AT\V1 command. Executing
this command at setup will cause the modem to
connect and return a message on line consisting of
<DTE speed> <modulation> <error protocol> <line
speed of connection>.
LEASED LINE OPTION
The CH1799LL is a leased line version of the CH1799.
Whereas the CH1799 requires an active voltage
bearing or wet PSTN line for normal operations
(typically, 48VDC on-hook line voltage), the CH1799LL
is designed to operate over a non-voltage bearing or
dry line.
The CH1799LL will only operate properly on a dry line.
Damage will occur if used on a wet line. The
CH1799LL does not support ring detect but does
support off-hook control.
Refer to Cermetek
Application Note # 116 for examples and instructions
to establish a connection over a leased dry line wire
pair. Note that the length of the leased line is limited
to 20,000 feet.
Use PSTN line protection as
2003 Cermetek Microelectronics, Inc.
Page 7
recommended in Figure 6B and in Cermetek
Application Note # 126.
Follow all applicable
requirements for FCC Part 68 compliance. The User
is responsible to ensure that FCC Part 68 compliance
is maintained.
As an alternative, the CH1799 will operate on a leased
line if the line is made wet by application of a DC
voltage. Refer to Cermetek Application Note # 114.
WARNING
Operation of the CH1799LL on a standard PSTN
line will damage the CH1799LL and void its
warranty. Further, operation of the CH1799LL on a
dry line without using proper current limiting circuitry
as outlined in Cermetek Application Note # 126 may
cause damage to the CH1799LL and will also void
its warranty.
Table 4. Pin Comparison of CH1786 and HS
Modem Family.
PIN
CH1786
HS Modem Family
1
RING
RING
2
TIP
TIP
3
RXA
T1
4
TXA
NC
5
SPK
SPK
6
NC
NC
7
NC
NC
8
SLEEP
OPEN*
9
NC
NC
10
TXD
TXD
11
RXD
RXD
12
OPEN*
V/D
13
DTR
DTR
14
DST
DSR
15
RI
RI
16
CTS
CTS (FX only)
17
DCD
DCD
18
HS
NC*
19
VCC
VCC
20
GND
GND
21
RST
RST
22
NC
RTS
NOTES:
1. * Indicates a difference between the CH1786 and
the HS Modem. The HS Modem may be directly
substituted for the CH1786 except in applications
where pins 8, 12, or 18 are used.
2. NC signifies ‘No Connect.’
3. Effective 31 March 2000, the HS Modem will no
longer support the HS indication function.
Therefore, pin 18 should be a ‘No Connect’ in all
applications.
Document No. 607-0003 Revision K3 (09/03)
Cermetek Microelectronics, Inc.
High Speed Modem and FAX Family
Table 3.
HS Modem Family Pin Descriptions.
PIN
NAME
I/O
FUNCTION
1
RING
I/O
TELCO/TELSET INPUT. Directly connects to the telephone line’s RING lead through a
user supplied RJ-11C jack.
2
TIP
I/O
TELCO/TELSET INPUT. Directly connects to the telephone line’s TIP lead through a user
supplied RJ-11C jack.
3
T1
I/O
ANALOG VOICE INJECTED. Input (See Figure 5). 2.2V P-P max. Let float if not used.
4
NC
-
No connection.
5
SPK
O
SPEAKER. Audio output for speaker. See speaker control diagram.
6
NC
-
No connection.
7
NC
-
No connection.
8
NC
-
No connection.
9
NC
-
No connection.
10
TXD
I
TRANSMIT DATA. Serial Transmit data input.
transmitted when a HIGH is asserted.
11
RXD
O
RECEIVE DATA. Serial Receive data output. Received marking or a binary 1 condition is
indicated by a HIGH.
12
NC
-
No connection.
13
DTR
I
DATA TERMINAL READY. Active LOW. Switching off DTR can either return modem to
command state, disconnect phone call, or reset the modem. DTR should be set LOW
when not used.
14
DSR
O
DATA SET READY. LOW indicates handshaking with a remote modem is in progress,
and/or the data carrier of a remote modem has been detected.
15
RI
O
RING INDICATION. This signal follows the frequency of the ringing signal and is normally
about 20 to 40 Hz for 2 seconds on with 4 seconds off.
16
CTS
O
CLEAR TO SEND. Active LOW. Indicates that the modem is ready to accept data from
the DTE.
17
DCD
O
DATA CARRIER DETECT. LOW indicates a data carrier from a remote modem has been
detected. This feature must be enabled using the &C1 command.
18
NC
-
No connection.
19
VCC
-
POWER SUPPLY. 5 Volts ± 5%. Note: Noise should be less than 25mV peak-to-peak.
20
GRD
-
GROUND. Note: Noise should be less than 25mV peak-to-peak.
21
RST
I
RESET. Active HIGH. This input must be asserted HIGH for at least 10-msec to reset the
modem. RESET is then returned to LOW for normal operation. If no system reset is
available, let this pin float to enable the internal reset.
Marking, or a binary 1 condition, is
22
I
REQUEST TO SEND. Active LOW. Used for flow control. Should be tied low if not used.
RTS
NOTE: (1) If VCC has a slow power up ramp time, the internal reset may be ineffective.
(2) Do not drive LED’s directly from any output. Use Buffers.
2003 Cermetek Microelectronics, Inc.
Page 8
Document No. 607-0003 Revision K3 (09/03)
Cermetek Microelectronics, Inc.
High Speed Modem and FAX Family
AT COMMAND APPLICATIONS
Example:
Dialing a Phone Number. The Dial command takes
the form Dn, where n is a string of characters. In the
simplest form, n will be only the digits of the phone
number to be dialed.
Enter:
Result:
Example:
Enter:
Dial Number.
ATD1234567<CR>
In response to this command, the HS Modem dials the
telephone number “123-4567” and then waits for a
carrier from the distant modem. If no carrier is
detected within a given time (the default time is 30
seconds), the HS Modem automatically releases the
line and sends a NO CARRIER result code. If a
carrier is detected, the HS Modem gives a CONNECT
result
code
and
goes
on-line,
permitting
communication with the distant modem.
Touch-tone dial 9, pause, go off-hook,
return for additional AT commands.
ATDT9, T;<CR>
OK<CR><LF>
Automatic Answering.
S0=0*
DO NOT ANSWER TELEPHONE
S0=1-254 ANSWER ON RING 1 TO RING 254
S0=255
ANSWER ON RING 255
*When S0 is set to 0, the modem will not auto-answer.
PHONE LINE CONNECTION GUIDELINES
1.
The HS Modem must be mounted in the final
assembly such that it is isolated from exposure to
any hazardous voltages within the assembly.
Adequate separation and restraint of cables and
cords must be provided.
The Dial command may also be issued without a
telephone number. ATD causes the modem to pick up
the telephone a line without dialing a number.
2.
Pause During Dialing. When placing a call from an
office with a telephone connected to a PBX, it may be
necessary to dial an access code (usually the digit 9)
to get an outside line. Inserting a comma in the
telephone number commands the modem to pause for
a specific length of time. The factory default pause
time is 2 seconds.
The circuitry from the HS Modem to the
telephone line interface must be provided in
wiring that carries no other circuitry other than
that specifically allowed in the FCC rules (such as
A and A1 leads).
3.
Connection to phone line should be made
through an RJ-11C jack.
4.
PCB traces from the modem’s RING and TIP pins
to the RJ-11C jack must be 0.1 inch spacing or
greater to one another and 0.2 inch spacing or
greater to all other traces. The traces should
have a nominal width of 0.020 inches or greater.
5.
The RING and TIP PCB traces should be as
short as possible and oriented to prevent
coupling other high speed or high frequency
signals present on the host circuit PCB.
6.
No additional circuitry other than that shown in
Figure 7 may be connected between the modem
module and the RJ-11C jack. Doing so will
invalidate the FCC approval.
7.
The HS Modem, the RJ-11C jack, the interfacing
circuitry and all PCB traces in between, must be
contained on a PCB with a 94 V-0 flammability
rating.
8.
The supplied FCC registration label must be
applied visibly on the outside of the product.
9.
The product’s User Manual must provide the user
with instructions for connection and use as
recommended in the FCC Registration Section
below.
Example:
Enter:
Result:
Dial 9, pause, dial number.
ATDT9, T1234567<CR>
OK<CR><LF>
Multiple commas may be used for a greater delay
time.
Touch Tone and Pulse Dialing. The modem can use
DTMF (touch-tones) T, or dial pulses P when dialing a
telephone number. If the dial command does not
specify which type to use, the modem defaults to the
type last specified. The power-on default value is T.
Example:
Enter:
Result:
Pulse dial 9, pause, touch-tone dial
number.
ATDP9, T1234567<CR>
OK<CR><LF>
Redial Last Number. Use A/, the repeat command,
to redial the last telephone number dialed when a busy
signal is received.
Go Off-Hook and Return to Command State. The
modem can be forced to reenter the command state
after going off-hook by issuing the ATDT command
with a semi-colon. This is useful when using the
modem with an independent DTMF tone generator.
2003 Cermetek Microelectronics, Inc.
Page 9
Document No. 607-0003 Revision K3 (09/03)
Cermetek Microelectronics, Inc.
High Speed Modem and FAX Family
CANADIAN APPROVALS
The HS Modem family is approvable for use by DOT to
CSA CS-03 Part I.
However, per Canadian
procedures, approval can only be granted after the HS
Modem has been installed into the end product.
Typically, Canadian approval is obtained by submitting
the final end product to an independent test house or
consultant for evaluation. The test house/consultant
then forwards the test results and applicable
documents to the regulatory agency. Cermetek offers
a list of consultants to assist with this process.
In addition to restriction notification, the FCC requires
that Cermetek make all repairs to all products in the
HS Modem family. If repairs are necessary after
installation of the HS Modem and the end product has
been delivered to the end user, the end product must
be returned to the end product supplier where the HS
Modem can be removed and then forwarded to
Cermetek for repair.
The following notice is
recommended and should be included in the end
product’s user manual.
FOR YOUR USER’S MANUAL
PAN-EUROPEAN TBR21 APPROVALS
The CH1799TBR/ETBR and CH2056TBR/ETBR
products have been designed to meet the
requirements of ETSI TBR – 021 Pan-European
Approval for Connection to Analogue Public Switched
Telephone Networks in addition to the FCC Part 68
conveyed approval, Canadian DOT CSA CS-03 Part I
compliance and UL 1950 Edition 3/CSA C22.2 950
recognition. Test reports (as required for CE marking)
demonstrating TBR21 compliance are available upon
request.
HS MODEM HANDLING AND ASSEMBLY
RECOMMENDATIONS
The HS Modem contains static-sensitive components
and should only be handled by personnel and in areas
that are properly protected against static discharge.
There are two mounting techniques that are
recommended for physically connecting the HS
Modem to a PCB:
1. Direct soldering.
2. Sockets.
Direct Soldering. The HS Modem may be wave
soldered onto a circuit card. All HS Modem products
are hermetically sealed and will not be harmed by
industry standard wave soldering processes.
Socketing. The socketing approach to mounting
eliminates cleaning and desoldering concerns. When
the socket is used, it must make a solid connection to
all pins. Failure to do so will cause unreliable or
intermittent operation. Also, steps should be taken to
assure that the module remains tightly seated in the
socket after the end product is shipped. Cermetek
recommends socket CES-150-01-T-S by Samtec, 50
pin strip socket.
FCC REGISTRATION
All products in the HS Modem family are registered
with the FCC (except the CH1799LL) under Part 68.
To maintain the validity of the registration, you must
serve notice to the end user of the product of several
restrictions the FCC places on the modem and its use.
2003 Cermetek Microelectronics, Inc.
Page 10
The Part 68 rules require the following (or equivalent)
be provided to the end user of the equipment
containing a DAA:
Type of Service. The (insert end product name) is
designed to be used on standard device telephone
lines. It connects to the telephone line by means of a
standard jack called the USOC RJ-11C (or USOC
RJ45S). Connection to telephone-company-provided
coin service (central office implemented systems) is
prohibited. Connection to party lines service is subject
to state tariffs.
Changes in Attestation Procedure for Plugs and
Jacks. (Name of applicant) attests that the network
interface plugs or jacks used on this equipment comply
with and will continue to comply with the mechanical
requirements specified in Part 68, Sub-part F,
specifically the dimensions, tolerances and metallic
plating requirements.
The compliance of these
connectors will be assured by purchase specifications
and incoming inspection. Documentation of such
specifications and/or inspections will be provided by
the FCC within 30 days of their request for the same.
Telephone Company Procedure. The goal of the
telephone company is to provide you with the best
service it can. In order to do this, it may occasionally
be necessary for them to make changes in their
equipment, operations or procedures.
If these
changes might effect your service or the operation of
your equipment, the telephone company will give you
notice, in writing, to allow you to make any changes
necessary to maintain uninterrupted service.
In certain circumstances, it may be necessary for the
telephone company to request information from you
concerning the equipment which you have connected
to your telephone line. Upon request of the telephone
company, provide the FCC registration number and
the ringer equivalence number (REN); both of these
items are listed on the equipment label. The sum of all
of the REN’s on your telephone lines should be less
than five in order to assure proper service from the
telephone company. In some cases a sum of five may
not be useable on a given line.
Consult your
telephone provider.
Document No. 607-0003 Revision K3 (09/03)
Cermetek Microelectronics, Inc.
High Speed Modem and FAX Family
If Problems Arise.
If any of your telephone
equipment is not operating properly, you should
immediately remove it from you telephone line, as it
may cause harm to the telephone network. If the
telephone company notes a problem, they may
temporarily discontinue service. When practical, they
will notify you in advance of this disconnection. If
advance notice is not feasible, you will be notified as
soon as possible.
When you are notified, you will be given the
opportunity to connect the problem and informed of
your right to file a complaint with the FCC. Contact
your local telephone service provider if you have any
questions about your phone. Line.
In the event repairs are ever needed on the (insert
your product name), they should be performed by
(insert your company name), or an authorized
representative or (insert your company name). For
information contact: (insert your company address).
DEFAULT
SPECS
STATUS,
PERFORMANCE
AND
Prior to delivery, Cermetek installs into each HS
Modem the following default Configuration Profile:
Default Connect Speeds are 14,400bps, 33,600bps
and 57,600bps for CH1794, CH1799 and CH2056
respectively
Serial port data rate auto baud enabled
Bell 212A operation at 1200bps
Parity – none
Auto answer disabled
Command echo ON
All result codes enabled – except \REL codes
Wait for dial tone before dialing – 2 seconds
Dials with touch-tone (T)
Detects busy signal (ATX4)
Full word result codes – non-extended
Pulse dial make/break ratio = 39/61-10pps
Test timer set to 0 seconds, test modes disabled
Inactivity timer set to 0 minutes
CTS always active
DSR is ignored
DCD is ignored
RTS to CTS delay - .01 seconds
DTR always active – hang up after transition
Long space disconnect disabled
Speaker enabled but off when receiving carrier
Speaker volume set to low
Local modem will not grant RDL request from remote
modem
Guard tones disabled
Minimum DTR pulse width = .05 seconds
Ring count – 00
Escape code character = 43 (+)
2003 Cermetek Microelectronics, Inc.
Page 11
Flash to on hook = 70 msec
Auto speed detection enabled
DTE connect speed, connect messages
Back space character = 08 (BS) Carriage return
character = 13 (CR)
Line feed Character = 10 (LF)
Duration of wait for dial tone =2 seconds
Duration of wait for carrier after dialing = 50 seconds
Carrier detect response time = 0.6 seconds
Escape code guard time = 1 second
Length of use after comma = 2.0 seconds
Last carrier to hang up delay = 1.4 seconds
DTMF interdigit delay = .095 seconds
Auto sync address or address detection =0
Connection detected at DTE – Highest speed
38,400kbps
Auto retrain enabled – 30 seconds attempts
MNP error correction mode can be negotiated (&Q5)
MNP – non-extended service selected
MNP error correction block size is 128 characters
selected
Data compression – negotiation enabled
Transmit break length is 0.3 seconds
All breaks are transmitted in sequence with data
Serial port flow control enabled = RTS/CTS
XON/XOFF flow control characters selected
Note: Upon power-up the HS Modem will recall
user profile 0 which may override some of the
above Factory Defaults. If desired the user may, at
their option, save the factory defaults in user
profile 0.
Table 5A. Summary of Non-Extended Result
Codes.
Result Code Form
n is ATXn
Command
Terse
Verbose or Long
0 1 2 3 4
or
Short
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 DIAL TONE
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
Document No. 607-0003 Revision K3 (09/03)
Cermetek Microelectronics, Inc.
High Speed Modem and FAX Family
Figure 5. Schematic Illustrating Implementation of Voice Injection Feature.
Table 5A. Summary of Non-Extended Result
Codes (Continuation).
Result Code Form
n is ATXn
Command
Terse
Verbose or Long
0 1 2 3 4
or
Short
17
CONNECT 38400
1 X X X X
18
CONNECT 57600
1 X X X X
19
CONNECT 115200
1 X X X X
20
CONNECT 230400
1 X X X X
22
Connect 75TX/1200RX
1 X X X X
23
Connect 1200TX/75RX
4 4 4 4 X
24
DELAYED
4 4 4 4 X
32
BLACKLISTED
X X X X X
33
FAX
X X X X X
35
DATA
Table 5B. CH1799 Extended Result Codes.
Result Code Form
n is ATXn
Command
Terse
Verbose or Long
0 1 2 3
or
Short
40
CARRIER
X X X X
44
CARRIER 1200/75
X X X X
45
CARRIER 75/1200
X X X X
46
CARRIER 1200
X X X X
47
CARRIER 2400
X X X X
48
CARRIER 4800
X X X X
49
CARRIER 7200
X X X X
50
CARRIER 9600
X X X X
51
CARRIER 12000
X X X X
52
CARRIER 14400
X X X X
53
CARRIER 16800
X X X X
54
CARRIER 19200
X X X X
55
CARRIER 21600
X X X X
56
CARRIER 24000
X X X X
57
CARRIER 26400
X X X X
58
CARRIER 28800
X X X X
2003 Cermetek Microelectronics, Inc.
4
Table 5B. CH1799
Extended
(Continuation).
Result Code Form
Terse
or
Short
59
61
62
63
64
66
67
69
76
77
80
84
91
Verbose or Long
CARRIER 16800
CARRIER 21600
CARRIER 24000
CARRIER 26400
CARRIER 28800
Compression: Class 5
Compression: V.24bis
Compression: None
PROTOCOL: NONE
PROTOCOL: LAPM
PROTOCOL: ALT
CONNECT 33600
CONNECT 31200
Result
Codes
n is ATXn
Command
0 1 2 3 4
1
1
1
1
1
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
IMPORTNAT NOTE
This note applies to Tables 5A, 5B, and 5C. 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. A numeral indicates
which less explicit message (verbose or short
form) will be output for that X option.
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Table 5C. CH2056 Extended Result Codes.
Result Code Form
n is ATXn
Command
Terse
Verbose or Long
0 1 2 3
or
Short
165
CONNECT 32000
X X X X
166
CONNECT 34000
X X X X
167
CONNECT 36000
X X X X
Page 12
4
X
X
X
Document No. 607-0003 Revision K3 (09/03)
Cermetek Microelectronics, Inc.
Table 5C. CH2056
Extended
(Continuation).
Result Code Form
Terse
or
Short
168
169
170
171
172
173
174
175
176
177
178
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
Verbose or Long
CONNECT 38000
CONNECT 40000
CONNECT 44000
CONNECT 46000
CONNECT 48000
CONNECT 48000
CONNECT 50000
CONNECT 52000
CONNECT 54000
CONNECT 56000
CONNECT 23040
CONNECT 28000
CONNECT 29333
CONNECT 30667
CONNECT 33333
CONNECT 34667
CONNECT 37333
CONNECT 38667
CONNECT 41333
CONNECT 42667
CONNECT 45333
CONNECT 46667
CONNECT 49333
CONNECT 50677
CONNECT 53333
CONNECT 54377
High Speed Modem and FAX Family
Result
Codes
n is ATXn
Command
0 1 2 3 4
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Table 6A. Summary of Basic AT Commands.
Command Function
A/
Re-execute command
A
Go off-hook and attempt to answer call
B0
Select V.22 connection at 1200kbps
B1
Sect Bell 212A connection at 1200kbps
C1
Return OK message
Dn
Dial modifier
P
Pulse Dial
T
Touch Tone Dial
W
Wait for Dial Tone
;
Return to Idle State
@
Wait for Quiet Answer Command
!
Flash Hook
,
Pause
0-9/ABC Dial Digits/Characters & wait
for credit card dial tone
^
Toggles calling tone
L
Redial last number
*
Star digit – tone dialing
S=n Dial the number and store in
Directory, n= 0 to 3
E0
Turn off command echo
E1
Turn on command echo
2003 Cermetek Microelectronics, Inc.
Page 13
Table 6A. Summary of Basic AT Commands
(Continuation).
Command
Function
H0
Initiate a hang-up sequence
H1
If on-hook, go off-hook and enter
command mode
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 hand shaking
and turn speaker off while receiving
carrier
M2
Turn Speaker on during hand shaking
and while receiving carrier
M3
Turn Speaker off during dialing and
receiving
Carrier and turn speaker on during
answering
N0
Turn off auto-mode detection
N1
Turn on auto-mode detection
O0
Go on-line
O1
Go on-line and initiate a retrain
sequence
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
Sn=v
Set default S-Register as default
V0
Report short form (terse) result codes
V1
Report long form (verbose) result
codes
W0
Report DTE speed
W1
Report line speed, EC protocol and
DTE speed
W2
Report DCE speed
X0 to X4
Report basic call progress result
codes, i.e. OK, CONNECT<RING,
NOCARRIER (also for busy, if
enabled, and dial tone not detected),
NO ANSWER and ERROR
Y0
Disable long space disconnect before
on-hook
Y1
Enable long space disconnect before
on-hook
Z0, Z1
The modem performs soft reset.
Restore stored profile 0 or 1 after
warm reset
&C0, &C1
Force DCD active regardless of the
carrier state or allow DCD to follow the
carrier state
&D0
Modem ignores DTR. (Default)
&D1
Modem assumes command state
&D2
Modem hangs up, assumes command
state and disables auto-answer
&D3
Modem assumes initialization state
Document No. 607-0003 Revision K3 (09/03)
Cermetek Microelectronics, Inc.
High Speed Modem and FAX Family
Table 6B. Summary of Basic AT Commands.
Command
Function
&F0
Restore Factory configuration 0
&F1
Restore Factory configuration 1
&G0
Disable guard tone
&G1
&G2
&K0
&K3
&K4
&K5
&K6
Command
%C3
Function
Enable both V.42bis 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 msec
&M0
Select direct asynchronous mode
&P0
Set 10pps pulse dial with 39%/61%
make/break
&p1
Set 10pps pulse dial with 33%/67%
make/break
&P2
Set 20pps pulse dial with 39%/61%
make/break
&P3
Set 20pps pulse dial with 33%/67%
make/break
&Q0
Select direct asynchronous mode
&Q5
Modem negotiates an error corrected
link
&Q6
Select asynchronous operation in
normal mode
&V
Display current configuration
&W0
Store the active profile in NVRAM
profile 0
&W1
Store the active profile in NVRAM
profile 1
&Y0
Recall stored profile 0 upon power up
&Y1
Recall stored profile 1 upon power up
&Zn=x
Store dial string x (to 31) to location n
(0-3)
%E0
Disable line quality monitor and auto
retrain
%E1
Enable line quality monitor and auto
retrain
%E2
Enable line quality monitor and
fallback
MNP10 COMMANDS
-K0
Disable MNP 10 extended services
-K1
Disable MNP 10 extended services
-K2
Disable MNP 10 extended services
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
Disable guard tone
Enable 1800 Hz guard tone
Disable DTE/DCE flow control
Enable RTS/CTS DTE/DCE flow
control
Enable XON/XOFF DTE/DCE flow
control
Enable transparent XON/XOFF flow
control
Enable both RTS/CTS & XON/XOFF
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 buffer
\K3
Send break to remote modem
immediately
\K5
Send break to remote modem in
sequence with tranmitted data
When modem receives \b in on-line command
state:
\K0, 1
Clear buffers & send break to remote
modem
\K2, 3
Send break to remote modem
\K4, 5
Send break to remote modem in
sequence with tranmitted data
When modem receives a break from remote
modem:
\K0, 1
Clear data buffers and send break to
DTE
\K2, 3
Send break immediately to DTE
\K4, 5
Send break with received data to
DTE
\N0
\N1
\N2
\N3
\N4
\N5
\V0
\V1
+MS
%C0
%C1
%C2
Select normal speed buffered mode
Select direct mode
Select reliable mode
Select auto reliable mode
Force LAPM mode
Force MNP mode
Connect messages are controlled by
the command settings X, W, and S95
Connect messages are displayed in
the single line format
Select modulation
ERROR CORRECTING COMMANDS
Disable data compression
Enable MNP 5 data compression
Enable V.42bis data compression
2003 Cermetek Microelectronics, Inc.
Page 14
Document No. 607-0003 Revision K3 (09/03)
Cermetek Microelectronics, Inc.
Register
S0
S1
S2
S3
S4
S5
S6
S7
S8
S9
S10
S11
S12
S13
S14
S15
S16
S17
S18
S21
S22
S23
S24
S25
S26
S27
S28
S30
S31
S32
S33
S34-S35
S36
S37
S38
S39
S40
S41
S42-S45
S46
S48
S82
S86
S95
High Speed Modem and FAX Family
Table 7. S-Register Summary.
Function
Range
Rings to Auto-Answer
0-255
Ring Counter
0-255
Escape Character
0-255
Carriage Return Character
0-127
Line Feed Character
0-127
Backspace Character
0-255
Wait Time for Dial Tone
2-255
Wait Time for Carrier
1-255
Pause Time for Dial Delay Modifier
0-255
Carrier Detect Response Time
1-255
Carrier Loss Disconnect Time
1-255
DTMF Tone Duration
50-255
Escape Prompt Delay
0-255
Reserved
--General Bit Mapped Options Status
--Reserved
--Test Mode Bit Mapped Option Status (&T)
--Reserved
--Test Timer
0-255
V.24/General Bit Mapped Options Status
--Speaker/Results Bit Mapped Options Status
--General Bit Mapped Options Status
--Reserved
--Delay to DTR Off
0-255
RTS-to-CTS Delay
0-255
General Bit Mapped Options Status
--General Bit Mapped Options Status
--Disconnect Inactivity Timer
0-255
General Bit Mapped Options Status
--XON Character
0-255
XOFF Character
0-255
Reserved
--LAPM Failure control
--Line Connection Speed
--Delay before Forced Hang up
0-255
Flow Control bit Mapped Options Status
--General Bit Mapped Options Status
--General Bit Mapped Options Status
--Reserved
--Data Compression Control
--V.42 Negotiation Control
--LAPM Break Control
--Call Failure Reason Code
0-255
Result Code Messages Control
---
2003 Cermetek Microelectronics, Inc.
Page 15
Units
Rings
Rings
ASCII
ASCII
ASCII
ASCII
Seconds
Seconds
Seconds
0.1 seconds
0.1 seconds
0.001 seconds
0.02 seconds
----------Seconds
--------Sec or 0.01 sec
0.01 seconds
----10 seconds
--ASCII
ASCII
------Seconds
-------------------
Saved
*
*
*
*
*
*
*
----------*
--------*
-------------
*
*
*
*
*
*
*
*
Default
0
0
43
13
10
8
2
50
2
6
14
95
50
--138 (8Ah)
--0
--0
52 (34h)
117 (75h)
62 (3Dh)
--5
1
73 (49h)
0
0
94 (C2h)
17 (11h)
19 (13h)
--7
0
20
3
104 (68h)
195 (C3h)
--138
7
128 (40h)
--0
Document No. 607-0003 Revision K3 (09/03)
Cermetek Microelectronics, Inc.
High Speed Modem and FAX Family
Figure 6. PSTN Line Interface for all HS Modems.
1. Currently Limiting PSTN Protection Line
Device. Currently limiting devices are mandatory
to meet UL safety standards.
To maintain
conveyed FCC Part 68 approval, the current
limiting components identified as F1 and F2 in
dashed Box #1 must also survive FCC Part 68
surge testing. Refer to Cermetek Application Note
#126, Supplemental PSTN Line Protection, for
more details. Refer to Application Note # 130,
Summary of Recommend Suppliers, for a list of
suppliers and associated part numbers.
A. A Polyfuse (rated at 0.15 amps) is preferred
because it resets automatically upon removal
of the current flow. Non-resettable devices
are also acceptable. Refer to Application Note
#130 for a complete list of recommended
vendors and associated part numbers.
B. Resistors (10Ω carbon film or 1/8 watt
minimum) may be used in Canada, as Canada
has no requirements that PSTN equipment be
operational after a Type B surge test.
C. Although CSA CS-03 Part 1 (Canada) follows
the requirements of FCC Part 68 (USA),
Cermetek recommends contacting DOT
(Canada) and/or a certified independent lab to
verify compliance. For Canada, use either
10Ω resistors (carbon film or SMD parts 1/8
watt minimum) as described in paragraph B
above.
2. Over Voltage and Lightning Protection.
A. Surge Protection is provided by internal
circuitry contained within all HS Modems
except the CH1799LL (see Figure 6). No
additional external components are required to
maintain conveyed FCC Part 68 approval for
all HS Modems (excluding the CH1799LL).
B. For CH1799LL, the required surge protection
(identified as D1 in dashed Box 2) must be
2003 Cermetek Microelectronics, Inc.
Page 16
supplied externally.
The purchaser must
include some form of surge protection as
described herein to maintain conveyed FCC
Part 68 approval. Refer to Application Note #
130 for a list of recommended suppliers.
C. In most environments, 2 terminal surge
suppressors (300V sidactor or equivalent) are
adequate. For severe environments, use an
external 3 terminal device with an earth
ground. DO NOT USE MOUs or transorbs
this purpose.
3. EMI/RFI Suppression.
No external EMI/RFI noise suppression circuitry is
required to maintain conveyed FCC Part 68
approval. However, additional suppression, if
required for other reasons, may be added as
described below in Sections 3A-3B without
adversely affecting FCC Part 68 approval.
A. To provide adequate EMI/RFI suppression,
the capacitor/inductor network contained in
dashed Box #3 should be located as close to
the RJ11 Jack as possible. Further, this
network should be provided with an excellent
ground path to the chassis.
B. Capacitors C1 and C2 should not exceed
0.005µf. They must have a rating of 1.5KV
and typically are 0.001µf ± 20%. Inductors L1
and L2 may be either individual inductors or a
dual inductor. Refer to Application Note #130
for a complete list of recommended vendors
and associated part numbers.
For UL
applications, choose capacitors and inductors
that are UL 1950 listed. The actual values of
the components used may vary depending on
the end product design.
Document No. 607-0003 Revision K3 (09/03)
Cermetek Microelectronics, Inc.
High Speed Modem and FAX Family
Table 8. HS Modem Electrical Specifications.
Symbol
Characteristic
Min.
Typ.
Max.
Units
4.5
5.0
5.5
V
VCC
Positive Supply Voltage
ICC Off Hook
(CH1794)
Nominal Operating Current @
ICC Off Hook
Nominal Operating Current @
(CH1799)
VCC = 5.5V when modem is Off Hook
VIH
High Level Input Voltage*
VIL
Low Level Input Voltage*
VT+
Positive Hysteresis Threshold for RESET Pin
2.5
V
VT-
Negative Hysteresis Threshold for RESET Pin
0.5
V
VOH
High Level Output (IOH = 0.5 mA)*
VOL
Low Level Output (IOL = 1.6 mA)*
0.6
V
IIN
Input Leakage Current (TXD, DTR, RTS)
100
µA
IOH
Input Current (RST)
500
µA
Cp
Capacitive Load (TXD, DTR, RTS)
10
pF
Capacitive Load (RST)
8
pF
VCC = 5.5V when modem is Off Hook
115.0
mA
185.0
mA
2.0
V
0.8
2.4
V
V
Test conditions: VCC = 5V ± 10%, Temp = 0°C to 70°F (unless otherwise stated).
*Output Load = 50 pF ± one TTL.
Table 9. HS Modem Electrical Specifications.
Parameter
Off Hook Impedance
Min.
Max.
20
Trans Hybrid Loss
Ring Voltage Loop
Typ.
Units
Ohm
25
110V
dB
600 Ohm, RXA, TXA
250V
VPP
On 48VDC line voltage for sustained
periods
100
mA
Does not apply to CH1799LL
600 Ohm
Line Loop Current – (Off
Hook)
20
Return loss @ 1000 Hz
15
dB
Ring Frequencies
40
Hz
Receiver Insertion Gain
-0.5
Transmit Power
Comments
0.0
+0.5
-9.5
dB
dBm
600 Ohm – Data Mode
sec
Delay
First Character After Reset
1.0
Inter Character Delay
20
50
msec
Between all command characters
Command Delay
100
200
msec
Between all AT command characters*
Minimum Reset Pulse
Duration
10
msec
If user supplied
* Note: Must wait for modem response before issuing new command.
2003 Cermetek Microelectronics, Inc.
Page 17
Document No. 607-0003 Revision K3 (09/03)
Cermetek Microelectronics, Inc.
Name
SPK
Model
CH1794
CH1794ET
CH1799
CH1799ET
CH1799LL
CH1799TBR
CH1799ETBR
CH2056
CH2056ET
CH2056TBR
CH2056ETBR
High Speed Modem and FAX Family
Type
O(DF)
Table 10. Analog Characteristics.
Characteristic
Minimum Load
Maximum Capacitive Load
Output Impedance
Output Voltage
D.C. Offset
Value
300 Ohms
0.01µf
10 Ohms
2.5 ± 1.6V
<20mV
Table 11. Summary HS Modem Family of Products.
Summary of Features
Operating Temperature
Full Function, 14.4kbps, FCC Part 68 Approved, UL 1950
0°C to + 70°C
Listed
Full Function, 14.4kbps, FCC Part 68 Approved, UL 1950
-40°C to +85°C
Listed
Full Function, 33.6kbps, FCC Part 68 Approved, UL 1950
Listed
Full Function, 33.6kbps, FCC Part 68 Approved, UL 1950
Listed
Full Function, 33.6kbps, FCC Part 68 Approved, UL 1950
Listed
Full Function, 33.6kbps, FCC Part 68 Approved, UL 1950
Listed,
TBR21 Compliant
Full Function, 33.6kbps, FCC Part 68 Approved, UL 1950
Listed,
TBR21 Compliant
Full Function, 56.0kbps, FCC Part 68 Approved, UL 1950
Listed
Full Function, 56.0kbps, FCC Part 68 Approved, UL 1950
Listed
Full Function, 56.0kbps, FCC Part 68 Approved, UL 1950
Listed,
TBR21 Compliant
Full Function, 56.0kbps, FCC Part 68 Approved, UL 1950
Listed,
TBR21 Compliant
2003 Cermetek Microelectronics, Inc.
Page 18
0°C to + 70°C
-40°C to +85°C
0°C to + 70°C
0°C to + 70°C
-40°C to +85°C
0°C to + 70°C
-40°C to +85°C
0°C to + 70°C
-40°C to +85°C
Document No. 607-0003 Revision K3 (09/03)
Cermetek Microelectronics, Inc.
High Speed Modem and FAX Family
NOTES:
1. All dimensions are inches.
2. Case dimensions are nominal + 0.02 inches.
3. Pin length is nominal + 0.03 inches.
4. Cermetek recommends that 0.04 inch diameter plated through holes are used with 0.060 inch
diameter pads.
5. Pin spacing are nominal.
6. Low Profile (0.550 inches maximum) case available 8/1/01 upon special request.
Cermetek reserves the right to make changes in specifications at any time and without notice. The information furnished by
Cermetek in this publication is believed to be accurate and reliable. However, Cermetek assumes no responsibility for its use, or for
any infringements of patents or other rights of third parties resulting from its use. No license is granted under any patents or patent
rights of Cermetek.
Printed in U.S.A
406 TASMAN DRIVE | SUNNYVALE CA 94089 | LOCAL: 408-752-5000 | TOLL FREE: 1-800-882-6271 | FAX: 408-752-5004
CERMETEK WEB SITE: http://www.cermetek.com | EMAIL: [email protected]
iModem Network WEB SITE: http://www.imodem.net/ or https://sunnyvale.imodem.net/
2003 Cermetek Microelectronics, Inc.
Page 19
Document No. 607-0003 Revision K3 (09/03)