CH1786 Family of Ultra Small 2400bps Modems
INTRODUCTION
FEATURES
The CH1786 family of modems are a full function,
Standards
ITU-U
V.22bis,V.22,Bell
FCC Part 68 approved 2400bps modem.
These
212,and Bell 103
modems provide a fast, easy and flexible way to
integrate a modem into any OEM product while
approvable
utilizing the minimum amount of PCB space (1.01 ”x
1.27 ”x 0.52 ”). The CH1786 family only requires two
external interfaces: a ITU-U V.24 serial interface that
can be routed directly to a UART, and a Tip and Ring
interface which goes directly to an RJ-11 jack for the
PSTN line connection.
The CH1786 can be
controlled with industry standard AT commands and,
peak surge protection minimum
hence,
is
compatible
with
available
industry
communication software.
standby mode
All CH1786 modems support asynchronous operation
at 2400bps, 1200bps, and 300bps to both Bell and
adaptive
and
fixed
compromise
ITU-U standards. The resident PSTN line interface,
equalization
or Data Access Arrangement (DAA), while being FCC
approved, is also Canadian DOT approvable and can
be approved in other countries that require 1500VAC
and telephone numbers
RMS isolation requirements per UL 1950 Edition 3.
The CH1786 family of modems operate off a single 5-
volt supply. The low power operation and automatic
CH1786 FAMILY
standby mode make these modems ideally suited for
CH1786
NVRAM, Voice/ Inject, Hermetic,
portable equipment. In addition, their small physical
Operating Temperature:
size affords maximum flexibility in equipment design.
0 ° C to +70 ° C
CH1786ET
NVRAM, Voice/
Inject, Hermetic,
Operating Temperature:
-40 ° C to +85 ° C
CH1786NH
Non-Hermetic, Operating
Temperature:
0 ° C to +70 ° C
Figure 1. Functional Block Diagram of CH1786.
The CH1786 comes with FCC Part 68 approval and is
shipped from the factory with an FCC Part 68 label
indicating
the
registration
number
and
ringer
equivalent.
This label should be prominently
displayed on the end product.
Figure 2. Voice/ Data Port Control
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CH1786 Family of Ultra Small 2400bps Modems
DESCRIPTION OF FUNCTIONAL BLOCKS
AT Command Set. A 40-character command line is
AND DISCUSSION OF BASIC OPERATIONS
supported. The command line starts with AT and
Figure 1 contains a functional block drawing of the
may contain standard or enhanced commands. The
CH1786. The CH1786 is a highly integrated, full-
commands are compatible with EIA Document
function
modem,
comprised
of
a
modulator/
TR302.2/88-08006.
demodulator, controller, NVRAM and an FCC Part 68
approved and UL 1950/CSA C22.2 950 listed PSTN
Serial Host Interface. The serial interface is a V.24
line interface.
(EIA-232) compatible interface. Ten Bits total: 1 start
bit, 1 stop bit, and eight data bits which can be either
Modulation/Demodulation and Modem Controller.
eight bits with no parity or seven odd or even with
These functions are provided by a monolithic modem
parity. The start bit is LOW going. RXD and TXD
integrated circuit.
This IC has built-in facilities to
data is non-inverted. See pin description in Table 2.
accommodate integrated AT command control and
contains the necessary resident interfaces for general
Speaker Interface.
The SPK output reflects the
communication and routing to the DAA.
receiver analog input and provides a signal that can
be used to monitor call progress. The SPK signal can
Telephone Line Interface or DAA. The CH1786
drive a 300 Ω load directly. Typically, the SPK signal
family of modems is designed to meet 1500VAC RMS
is input into an audio power amplifier and the
isolation and provide 2122V peak surge protection.
amplifier, in turn, drives the speaker coil.
The
Consequently, the CH1786 satisfies U.S. FCC Part
speaker is activated with the ATMn command. The
68
and
DOT
CSA
CS-03
Part
I
Canadian
speaker volume is adjusted using the ATLn
requirements, and will meet other international
command, where n is 0, 1, 2, or 3.
Increasing
approval agency requirements that specify these
numbers correspond to higher volume.
Figure 6
levels of isolation.
indicates one method of driving an external 8 Ω
speaker.
With the exception of the U.S., most countries
(including Canada) require submission of the final
Phone Control. Cermetek’s CH1786 contains a pin
product or system containing the CH1786 to the
called Voice or Data (V/D). The V/D pin toggles high
appropriate governing regulatory agency for approval.
when the modem goes off hook. This pin can be
Typically this is accomplished by submitting the final
used to activate a relay which can switch a telephone
end product to an independent test house or
on or off the Tip and Ring incoming PSTN lines. This
consultant for evaluation.
The test house or
feature allows any telephone associated with the
consultant then forwards the test results and
CH1786 to be disconnected when a data call is in
applicable documents to the regulatory agency. Call
progress, thereby preventing the data from being
Cermetek for a list of suggested consultants.
disturbed by an inadvertent telephone pick-up. See
Figure 2.
Non-Volatile RAM (NVRAM). The NVRAM present
on the CH1786 is sufficient to store up to two user
Speed and Parity Selection. Prior to call initiation,
customized modem configurations.
The AT&Wn
the host controller trains the modem to the host
command will store the active modem configuration in
speed (2400,1200 or 300bps) and parity (odd, even,
the selected NVRAM locations by specifying an n of 0
mark, space, or none) via a host-initiated training
or 1.
sequence. This training also sets the speed of the
data
for
originate
calls.
The
CH1786
will
The
AT&Yn
command
selects
the
modem
automatically adjust to the originator’s speed when
configurations to be automatically recalled and made
answering calls.
active upon a reset or power up.
The ATZn
command immediately recalls and activates a stored
The CH1786 matches the host’s parity when it returns
configuration. Refer to Tables 4, 5 and 6 for storable
status messages to the host.
During a data
S-Registers and available commands.
connection, however, the modem passes parity
through without interpretation or alteration.
The NVRAM can save up to four telephone numbers
with up to 36 digits or modifiers in each telephone
Sleep Mode. To minimize power consumption, the
number. The AT&Zn=s command will store s, the
CH1786 includes a power down feature called Sleep
telephone number dial string. The individual NVRAM
Mode.
When
activated,
the
CH1786
will
telephone number storage locations are selected by
automatically enter Sleep Mode after 0 to 254
specifying an n of 0, 1, 2, or 3.
The ATDTS=n
seconds of inactivity. The inactivity delay is selected
command will cause the modem to dial the stored
using the ATS24 command.
The CH1786 is
telephone number in location n. NVRAM is not
delivered from the factory with a 5 second inactivity
available on the CH1786LC or CH1786NH.
delay enabled (i.e., ATS24=5 ). The CH1786 returns
SUPPORT FEATURES
to normal operation when a ring signal is received or
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CH1786 Family of Ultra Small 2400bps Modems
upon an input low signal on the TXD pin.
pin becomes active. The CH1786ET products can
ATS24=255 disables the Sleep Mode and is the
thus be powered down to zero.
default if no value is set in register S24.
Table 1. Connection Rates.
A SLEEP output signal is available to control power to
Answering
Connection Rate Resulting
external devices. In Figure 6, a FET controlled by the
Modem Initial
When Calling Modem Initial
SLEEP signal turns of the external speaker amplifier
Trained Rate
Rate Is:
when the CH1786 enters Sleep Mode.
In Sleep
300
1200
2400
Mode, power is reduced to approximately 50% of
300
300
1200
1200
normal operating power.
1200
300
1200
1200
2400
300
1200
2400
Guard Tone. A guard tone of 550 Hz or 1800 Hz can
be generated at 6 dB or 9 dB below the transmit level,
respectively, by using the &Gn command. Refer to
“Cermetek AT Commands and S-Registers reference
Guide”
or
the
Cermetek
web
site
at
http://www.cermetek.com.
Answer Tone. A ITU-U (2100 Hz) or Bell (2225Hz)
answer tone is generated depending on the selected
configuration. Refer to “Cermetek AT commands and
S-Registers Reference Guide” or the Cermetek web
site at http://www.cermetek.com.
Data Encoding. The data encoding conforms to ITU-
U recommendations V.22bis or V.22, or Bell212A, or
103, depending on the selected configuration. Refer
to
“Cermetek
AT
commands
and
S-Register
Reference Guide” or the Cermetek web site at
http://www.cermetek.com.
Line Equalization. Transmitter and receiver digital
filters compensate for delay and amplitude distortion
Figure 3. Zero Power Operation.
during operation on nominal phone lines. In addition,
automatic adaptive equalization in the receiver
Referring to Figure 3, the controller activates the relay
minimizes the effects of inter symbol interference.
switch, supplying power (+5V) to the CH1786ET. In
this configuration, the ring signal is used to “wake up”
Transmission Speed.
In normal operation, the
the CH1786ET when the CH1786ET is in the power
originating modem initiates the call and attempts to
down state.
connect to the answering modem at a speed
The pins of the CH1786ET will be in an undefined
established by the originating modem’s controller
state when power is switched off. This must be taken
prior to call initiation. This is referred to as the Initial
into consideration to assure that no unwanted signals
Trained Rate. Upon receiving the call, the answering
are presented to the CH1786ET during power down.
modem will attempt to connect to the originating
modem at its Initial Trained Rate. If these two rates
Ring Indicator (RI). The RI pin follows the frequency
are identical, the connection is made. If the speeds
of the ring signal and toggles low when the CH1786
differ, the answering modem must adjust its rate or
detects an incoming call. The ring signal is typically
terminate the call. Table 1 indicates the connection
20 to 30 Hz and is on for 2 seconds and off for 4
rate that will result when the calling modem’s Initial
seconds. Although not TTL compliant, the RI pin can,
Trained Rate and the answering modem’s Initial
nonetheless, be utilized to activate external circuitry
Trained Rate are different.
including the external RST pin.
NOTE
When using the RI pin, it is recommended that a
A 2400-baud connection rate will only result if both
Schmitt Trigger or the Isolated Envelope Detect
modems are initially set at 2400 baud.
Circuit in Figures 3 or 5 be placed between the RI pin
and the external load.
Zero Power Mode (CH1786ET only).
If an
application calls for zero power during standby
Power Supply. The CH1786 modem module is a
periods, the power may be switched off using external
complex set of sub-systems. During the course of
circuitry and then reapplied when the CH1786’s RI
normal operation the CH1786 decodes analog signals
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CH1786 Family of Ultra Small 2400bps Modems
from the telephone line that are in the millivolt range.
Enter: ATS7=255<CR>
Disables data-carrier time
Steps must be taken by the user to guarantee that
Result: OK
out
power supply noise on all supply lines, including
ground, does not exceed 50 mV peak to peak. Any
Enter: ATS10=255<CR> Disables lost-carrier time
frequency between 20 kHz and 150 kHz must be less
Result: OK
out
than 500 micro volts peak.
If necessary, use
dedicated power and ground planes.
Failure to
The following command sequences illustrate
provide such operating conditions could cause the
implementation of common Voice/Tone Port
CH1786 to malfunction or to function erratically.
applications.
The CH1786 requires a single +5V ±5% supply. It is
1. To answer a voice call.
recommended that by-pass capacitors be placed on
(a) Enter: ATH1<CR>
the power supply as close to the modem’s supply
Result: OK
input as practical.
It’s recommended a 10 µ F
Tantalum capacitor in parallel with a 0.01 µF ceramic
(b) Drive V.INJ. HIGH to activate relay.
capacitor be used.
(c) Begin voice conversation.
Voice/DTMF Tone Injection Port.
The CH1786
2. To switch to data mode.
provides two pins to allow the user to share the
(a) Drive V.INJ. LOW
telephone line interface associated with the modem
(b) At the originate modem:
for voice and DTMF applications. Figure 4 contains a
Enter: ATX1<CR>
schematic indicating one possible configuration for
Result: OK
voice/ tone utilization.
3. To disconnect (hang-up) a voice call or a data
WARNING
call.
The CH1786 has been FCC Part 68 approved as a
(a) Enter: ATH<CR>
data modem only. Utilization of the Voice/DTMF
Result: OK
Tone Port requires further registration. FCC will
require that the system, including the CH1786 and
4. To place a call to 1234567 using the CH1786’s
the handset or DTMF transceiver, adhere to Part 68
DTMF tone generator.
rules.
Voice/Tone Injection is not active on
(a) Enter: ATDT1234567;C0<CR>
CH1786NH.
Result: OK
(b) Drive V.INJ. HIGH
Typically, voice communication would precede data
communications.
For this case, the following
commands should be used to configure the CH1786
MODEM CONTROL
(Refer to Figure 4):
The CH1786 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 can be read on
pin RXD.
This message indicates command
completion status. Refer to Table 3 for a complete
list of status messages.
INITIALIZING THE MODEM
Before commands may be sent to the CH1786, the
CH1786 must be initialized. Initialization is a two step
activity consisting of:
1. Hard Reset. This is accomplished by applying a
hardware reset pulse to pin RST or by switching
the power off and then back on.
2. Initial modem training.
The CH1786 must be
Figure 4. Voice/Tone Injection.
trained to the host’s speed (2400, 1200, 300bps)
and parity (odd, even, mark, space or none).
Enter: ATS0=<CR>
Disables auto-answer
Result: OK
These activities are briefly described below.
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CH1786 Family of Ultra Small 2400bps Modems
Reset. Upon applying power to the CH1786, the
<CR> represents carriage return (ASCII 13
CH1786 automatically generates an internal reset
or HEX 0D).
pulse. The user may also reset the modem externally
by applying a high-going reset pulse to the RST pin
When entering commands to the modem, the
for at least 10ms after the +5V power supply has
backspace character-control-H (ASCII 8 or HEX 08)
stabilized. Delay sending commands to CH1786 for
may be used to edit mistakes. AT and A/ may not be
200ms after reset has been initiated to allow the
edited.
Multiple commands may be placed in the
CH1786 time to properly reconfigure.
command line. A command line may be as long as
40 characters, excluding the letters AT . By way of
Training the Modem. Each modem must be trained
example, the command below instructs the CH1786
to match its host’s speed and parity so that it is able
to configure itself to not echo characters when in
to recognize serial asynchronous commands sent to it
command mode E0 and then put itself in answer
by the host’s is UART. The host must retrain the
mode A .
modem each time a reset pulse is applied on RST or
after a RESET serial command has been issued.
Enter: ATE0A<CR>
Result: OK
Modem Training Command Sequence.
The
CH1786 is trained by sending it the following
AT Command Set. The available command set is
sequence:
divided into four types of commands: dial modifiers,
basic
commands,
ampersand
and
percent
Enter: AT<CR>
commands. Refer to the complete list in Table 5.
Result: OK
Where: A and T may be either upper or lower case
AT Command Data Rate. With the serial interface,
but must be the same case.
the rate is speed sensed for parity and format.
<CR> represents carriage return
The AT sequence is referred to as an attention
THE STATUS MESSAGES
sequence. The CH1786 will respond with one of the
The CH1786 responds with a status message after
following status messages, depending on whether it
each command is executed. This status message
is optioned for Terse (abbreviated) or Verbose
may either be a single digit followed by a carriage
(English) status messages.
return or a carriage return and line feed with a
message in English, followed by a carriage return and
Result: 0<CR> (Terse)
line feed.
or
The basic status code subsets are enabled with the
Result:
<CR><LF>OK<CR><LF> (Verbose)
Xn command.
Where n=0,1,2,3,4 establishes the
Where:
<CR> represents carriage return (ASCII 13
result codes allowed by the user.
or HEX 0D).
<LF> represents line feed (ASCII 10 or
X0:
Result Codes 0, 1, 2, 3, 4 allowed
HEX 0A).
X1:
Result Codes 0, 1, 2, 3, 4, 5, 10 allowed
X2:
Result Codes 0,1, 2, 3, 4, 5, 6, 10 allowed
After responding with an OK, the CH1786 is in idle
X3:
Result Codes 0, 1, 2, 3, 4, 5, 7, 10 allowed
mode and is ready to accept additional commands.
X4:
Result Codes 0, 1, 2, 3, 4, 5, 6, 7, 10 allowed.
An alternate attention sequence A/ may be sent
which behaves much like the AT sequence except
NOTE
that it causes the previously entered command
The CH1786 is factory set to X4, which allows all
specified with an AT prefix to be executed. When
result codes.
given, both the AT and A/ must be in upper case
ASCII.
No carriage return is needed for the A/
command.
MODEM STATES
The CH1786 can be in either command mode or data
THE COMMAND FORMAT
mode. When the modem is idle, it is in command
Typical commands consist of three elements: the
mode by default and will recognize commands.
attention sequence, the commands themselves, and
When data transmission is in progress, the CH1786 is
a terminating carriage return.
in the data mode state and will not recognize
commands.
To force the CH1786 to recognize
AT[commands]<CR>.
commands, the host must send an escape sequence
Where: AT represents attention sequence.
to the CH1786 forcing it out of data mode and into
[Commands] represents command strings.
command mode.
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CH1786 Family of Ultra Small 2400bps Modems
Figure 5. CH1786 Application Diagram
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CH1786 Family of Ultra Small 2400bps Modems
Table 2. CH1786 Pin Descriptions
PIN
NAME
TYPE
FUNCTION
1
RING
I/O
RING . Directly connects to the telephone line’s Ring lead through a user supplied
RJ-11C jack.
2
TIP
I/O
TIP . Directly connects to the telephone line’s Tip lead through a user supplied RJ-
11C jack.
3
RXA
O
ANALOG VOICE INJECTED . Receive Signal. Let float if not used. Not active in
CH1786NH.
4
TXA
I
ANALOG VOICE INJECTED . Transmit Signal. Let float if not used. Not active in
CH1786NH.
5
SPK
O
SPEAKER . Audio output for speaker. See speaker control schematic in Figure 6.
6
NC
-
No connection.
7
NC
-
No connection.
8
SLEEP
O
SLEEP . A LOW indicates CH1786 is in low power idle mode. Used to control
power to other devices. See Figure 6. Register S24 is the sleep timer register.
When the CH1786 is inactive for a period of time specified by S24, the CH1786 will
power down by about 50% of its normal operating power. During power down, all
I/O lines become undefined. The CH1786 products are shipped from the factory
with a 5 second inactivity timer (ATS24=5) enabled.
9
NC
-
No connection.
10
TXD
I
TRANSMIT DATA . Serial Transmit data input. Marking or a binary 1 condition is
transmitted when a HIGH is asserted.
11
RXD
O
RECEIVE DATA .
Serial Receive data output.
Received marking or binary 1
condition is indicated by HIGH.
12
V/D
O
VOICE/DATA . Used to switch between telephone and modem line use. In a typical
application, V/D active HIGH opens the normally closed voice injection relay and
disconnects the handset from the telephone line. HIGH indicates the CH1786 is off-
hook and online. Therefore, this pin also reflects the state of the off-hook relay of
the CH1786. See Figure 2.
13
DTR
I
DATA TERMINAL READY . Active LOW. Switching off DTR can either return
modem to command state, disconnect phone call, or reset 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 . Ground if not using the FAX option. Reserved for flow control
when using FAX option. CTS only active on CH1786 when S24=255.
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CH1786 Family of Ultra Small 2400bps Modems
Table 2. CH1786 Pin Descriptions Continuation
PIN
NAME
TYPE
FUNCTION
17
DCD
O
DATA CARRIER DETECT . LOW indicates a data carrier from a remote modem is
detected. Must be enabled using the &C1 command.
18
HS
O
SPEED INDICATION . HIGH speed select output. A low on this pin indicates the
modem is operating at 2400bps.
19
VCC
-
POWER SUPPLY . 5 volts + 5% Note: Noise should be less than 50mV peak to
peak.
20
GND
-
GROUND . Note: Noise should be less than 50mV peak to peak.
RST
1
21
I
RESET . Active HIGH. This input must be asserted HIGH for at least 10 ms to reset
the modem. RESET is then returned LOW for normal operation. If no system reset
is available, let this pin float to enable internal reset.
22
NC
-
No connection required. For CH179X or CH2056 compatibility, connect to GND or
use as an active LOW input for request to send ( RTS ) functionality for CH179X/2056
products.
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.
Table 3. Summary of Result Codes and Meanings.
Result Codes
Status Message
Meaning
0
OK
Command Executed
1
CONNECT
Carrier detected at 300bps
2
RING
Ring Detected
3
NO CARRIER
Did not detect carrier
4
ERROR
Entry error
5
CONNECT 1200
Carrier detected at 1200bps
6
NO DIAL TONE
Off-hook, but no response after 5 seconds
7
BUSY
Busy signal detected
10
CONNECT 2400
Carrier detected at 2400bps
The escape sequence consists of a “guard time” (a
The CH1786 will stay off-hook with its carrier on after
period where no characters are sent to the modem),
the escape sequence is received. It will return an OK
followed by 3 escape characters, followed by another
status message when it is ready to accept
guard time. The guard time is set by register S12.
commands. The CH1786 may be put into data mode
The escape character code is set in register S2. At
by issuing the command ATO<CR> .
power-up, the guard time is set to 1 second minimum,
and the escape character is set as “+.” There is no
minimum delay between characters but the maximum
delay is set by register S12.
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CH1786 Family of Ultra Small 2400bps Modems
AT COMMAND APPLICATIONS
Example: Use A/ , the repeat command, to redial the
Dialing A Phone Number. The Dial command takes
last telephone number dialed.
the form Dn , where n is a string of characters. In the
Enter:
A/
simplest form, n will be only the digits of the phone
Result:
ATDT1234567R<CR> Previous command
number to be dialed.
OK
line executed
Example: Tone Dial number.
Return to Command State.
Use ; to return to
Enter:
ATD1234567<CR>
command mode offer dialing.
Result:
OK
Example: Touch-tone dial 9, pause, dial number,
In response to this command, the CH1786 dials the
return to Command.
telephone number “123-4567” and then waits for a
Enter:
ATDT9,1234567;<CR>
carrier from the distant modem.
If no carrier is
Result:
OK
detected within a given time (the default time is 30
seconds), the CH1786 automatically releases the line
Automatic Answering. The SO register controls the
and sends a NO CARRIER result code. If a carrier is
number of rings that must occur before the modem
detected, the CH1786 gives a CONNECT result code
answers a call. The register may range in value from
and goes on-line, permitting communication with the
0 to 255.
distant modem.
S0 =
0 DO NOT ANSWER TELEPHONE
S0 =
1 ANSWER ON RING 1
The Dial Command may also be issued without a
S0 =
2 ANSWER ON RING 2
telephone number. ATD causes the modem to pick
S0 =
3 ANSWER ON RING 3
up the telephone line without dialing a number.
S0 =
255 ANSWER ON RING 255
Pause During Dialing. When placing a call from an
When S0 is set to 0, the modem will not auto-answer.
office with a telephone connected to a PBX, it may be
necessary to dial an access code (usually the digit 9)
The Serial Interface Lines. The CH1786 supports a
to get an outside line.
Inserting a comma in the
full EIA-232D/V.24 serial interface. Signal levels are
telephone number instructs the modem to pause for a
TTL rather than EIA-232D level compatible, which
specific length of time. The factory set default pause
allows direct connection of the CH1786 to the host
time is 2 seconds.
UART without the need for level translation circuitry.
See Table 2 for a complete pin description.
Example: Pulse Dial 9,pause, dial number.
Enter:
ATDP9,1234567<CR>
The CH1786 is controlled by sending it serial
Result:
OK
commands over TXD and its status determined by
monitoring the serial status messages returned on
Multiple commas may be used to generate integer
RXD. DTR is optionally used to reset, terminate calls
multiples of the specified delay time.
or return CH1786 to command mode.
Originate a Call in Answer Mode. The D command
All other serial interface lines may be utilized for the
forces the modem into originate mode. To call an
convenience of a particular application but are not
originate-only modem, dial the number and set the
required by the CH1786.
Unused outputs (from
modem to answer mode via the R command (reverse
modem) should be left unconnected. Unused inputs
originate). This is done by including an R at the end
should be set to the proper logic level. See Table 2.
of the telephone number.
Fax Modes. The CH1786 Product Family supports
Example: Change modem
from original-only
to
Send and Receive FAX. The modes and rates are
answer mode.
determined by the AT+F commands. Refer to Table
Enter:
ATDT1234567R<CR>
6A.
Result:
OK
FAX modem processing is explicitly defined in ITU-U
Multiple commas may be used to generate integer
V.29, ITU-U V.27, and ITU-U V.21 recommendations.
multiples of the specified delay time.
All modulation, wave-form spectrum, and data
processing functions conform to the appropriate
Redial Last Number.
The repeat command is a
specifications.
convenient way to execute the previously entered
command line.
2004 Cermetek Microelectronics, Inc.
Page 9
Document No. 607-0004 Revision L4 (08/04)
Cermetek Microelectronics, Inc.
CH1786 Family of Ultra Small 2400bps Modems
Table 4.
S-Register Summary.
Firmware
Factory
Register
Description
Range
Units
Saved
Defaults
Defaults
S0
Ring to Answer On
0-255
rings
*
000
001
S1
Ring Count
0-255
rings
000
000
S2
Escape Code Character
0-127
ASCII
043
043
S3
Carriage Return Character
0-127
ASCII
013
013
S4
Line Feed Character
0-127
ASCII
010
010
S5
Back Space Character
0-32, 127
ASCII
008
008
S6
Maximum Wait Time for Dial Tone
2-255
s
002
002
S7
Maximum Wait Time for Data Carrier
1-255
s
030
030
S8
Pause Time for Comma
0-255
s
002
002
S9
Carrier Detect Response Time
1-255
1/10s
006
006
S10
Lost Carrier to Hang-up Delay
1-255
1/10s
014
014
S11
DTMF Dialing Speed
50-255
ms
095
095
S12
Escape Code Guard Time
0-255
1/50s
050
050
S13
Reserved
-
-
-
000
000
S14
Bit Mapped Options Register
Bit Mapped
none
*
170 (AAH)
170 (AAH)
S15
Reserved
-
-
-
000
000
S16
Modem Test Options
Bit Mapped
none
000
000
S17
FAX Mode Null Byte Timer
0-255
4ms incr
000
000
S18
Test Timer
0-255
s
*
000
000
S19
Protocol Interface Speed
0-1
none
000
000
S20
FAX Mode Inactivity Timer
0-127
s
000
000
S21
Bit Mapped Option Register
Bit Mapped
none
*
000
096 (06H)
S22
Bit Mapped Option Register
Bit Mapped
none
*
118 (76H)
118 (76H)
S23
Bit Mapped Option Register
Bit Mapped
none
*
007 (07H)
023 (17H)
S24
Sleep Mode Inactivity Timer
0-255
s
000
000
S25
Delay to DTR Off
0-255
0.1 or 1s
*
005
005
S26
RTS to CTS Delay Interval
0-255
0.01s
*
001
001
S27
Bit Mapped Option Register
Bit Mapped
none
*
064 (40H)
064 (40H)
S28
Bit Mapped Option Register
Bit Mapped
none
*
000
001
NOTES:
1. Parameters indicated with a (*) in the Saved column may be stored in User Profile n=0, 1 by executing
the appropriate &Wn command.
2. A stored Profile is a subset of allowed parameters and is comprised of those parameters displayed
with the &V command.
3. Factory Default values that are different from the Firmware Default values are highlighted in BOLD .
4. Restore Factory Default values using Zn command.
5. Restore Firmware Default values using &Fn command.
NOTE
The CH1786LC and CH1786NH products do not contain NVRAM and, therefore, do not support data storage after
power down. A detailed definition of all commands and S-Registers is available from Cermetek Microelectronics,
Inc. Refer to Cermetek Document AT Commands and S-Registers Reference Guide or access our website at
www.cermetek.com.
2004 Cermetek Microelectronics, Inc.
Page 10
Document No. 607-0004 Revision L4 (08/04)
Cermetek Microelectronics, Inc.
CH1786 Family of Ultra Small 2400bps Modems
Table 5. CH1786 AT Command Set Summary.
Table 6C. Ampersand and Percent Commands.
Basic
Function
Ampersand
Commands
Commands
Function
AT
Attention Code
&Cn*
Data Carrier Detect Option
A
Answer command
&Dn*
Data Terminal Ready Option
A/
Repeat last Command
&Fn
Restore Active Profile
Bn*
Communications Standard Option
&Gn*
Guard Tone Option
D
Dial Command
&Pn*
Make to Break Ratio Section
E*
Off-Line Character Echo Option
&Sn*
Data Set Ready Option
Hn
Switch Hook Control Option
&Tn
Test Command Option
Ln*
Speaker Volume Option
&V
View Active Configuration
Mn*
Speaker Control Option
&Wn*
Store Active Profile
On
On-Line Command
&Yn*
Set Profile to be used after hard
Qn*
Result Code Display Option
reset
Sn
Select an S Register
&Zn*
Store Telephone Numbers
Sn=
Write to an S Register
Sn?
Read an S Register
Vn*
Result code Form Option
PHONE LINE CONNECTION GUIDELINES
Xn*
Result Code Set/Call Progress
1. The CH1786 must be mounted in the final
Option
assembly such that it is isolated from exposure to
+++
Escape Sequence
any hazardous voltages within the assembly.
,
Pause
Adequate separation and restraint of cables and
?
Returns Last addressed S-Register
cords must be provided.
Yn*
Long Space Disconnect Option
Fn
On Line Echo character Option
2. The circuitry from the CH1786 to the telephone
Zn
Restore Active Profile
line interface must be provided in wiring that
carries no other circuitry other than that
specifically allowed in the FCC rules (such as A
Table 6A. FAX Command Set Summary.
and A1 leads).
FAX Command
Function
+FCLASS=n
Select Service Class
3. Connection to phone line should be made
+F<command>?
Report Active Configuration
through an RJ-11C jack.
+F<command>=?
Report Operating Capabilities
+FAA=n
Data/Fax Auto Answer
4. PCB traces from the modem’s RING and TIP pins
+FF
Enhanced Flow Control
to the RJ-11C jack must be 0.1 inch spacing or
+FTS=n
Stop Transmission and Wait
greater to one another and 0.2 inch spacing or
+FTM=n
Transmit Data
greater to all other traces.
The traces should
+FTH=n
Receive Data
have a nominal width of 0.020 inches or greater.
+FTH=n
Transmit Data with HDLC
Framing
5. The RING and TIP PCB traces should be as
+FRH=n
Receive Data with HDLC
short as possible and oriented to prevent
Framing
coupling other high speed or high frequency
+FRT=n
Receive Test Data
signals present on the host circuit PCB.
+FTTn=m
Transmit test Data
6. No additional circuitry other than that shown in
Table 6B. Dial Modifiers Summary.
Figure 7A or 7B may be connected between the
modem module and the RJ-11C jack. Doing so
Dial Modifiers
Function
will invalidate the FCC approval.
P
Pulse Dial
R
Originate Call in Answer Mode
7. The CH1786LC, and CH1786NH (only) requires
T
Touch Tone Dial
external surge protection (see Figure 7B). This is
W
Wait for Dial Tone
mandatory to maintain FCC Part 68 conveyed
;
Return to Idle State
approval.
@
Wait for Quiet Answer
Command
8. The CH1786, the RJ-11C jack, the interfacing
!
Flash Hook
circuitry and all PCB traces in between, must be
,
Pause
contained on a PCB with a 94 V-0 flammability
0-9
Allowed Dial Digits/Characters
rating.
A,B,C,D, #, *
2004 Cermetek Microelectronics, Inc.
Page 11
Document No. 607-0004 Revision L4 (08/04)
Cermetek Microelectronics, Inc.
CH1786 Family of Ultra Small 2400bps Modems
9. The supplied FCC registration label must be
FCC REGISTRATION
applied visibly on the outside of the product.
All products in the CH1786 family are registered with
the FCC
(Federal Communications Commission)
10. The product’s User Manual must provide the user
under Part 68.
To maintain the validity of the
with instructions for connection and use as
registration, you must serve notice to the end user of
recommended in the FCC Registration Section
the products of several restrictions the FCC places on
below.
the modem and its use.
In addition to restriction notification, the FCC requires
CH1786 HANDLING AND ASSEMBLY
that Cermetek make all repairs to all products in the
RECOMMENDATIONS
CH1786 family.
If repairs are necessary after
The CH1786 contains static-sensitive components
installation of the CH1786 in the end product and the
and should only be handled by personnel and in
end product has been delivered to the end user, the
areas that are properly protected against static
end product must be returned to the end product
discharge.
The
two
recommended
mounting
supplier where the CH1786 can be removed and then
techniques for physically connecting the CH1786 to a
forward to Cermetek for repair. The following notice
PCB are discussed below.
is recommended and should be included in the end
product’s user manual.
FOR YOUR USER’S MANUAL
The FCC Part 68 rules require the following (or
equivalent) be provided to the end user of equipment
containing a DAA.
Type of Service . The (insert end product name) is
designed to be used on standard device telephone
lines. It connects tot he 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
Figure 6.
Speaker Control Circuit: Optional to
Jacks. (Name of applicant) attests that the network
allow for call progress monitoring.
interface plugs or jacks used on this equipment
comply with and will continue to comply with the
Direct Soldering.
The CH1786 may be wave
mechanical requirements specified in Part 58, sub-
soldered.
All CH1786 products are hermetically
part F, specifically the dimensions, tolerances and
sealed (except the CH1786NH) and will not be
metallic plating requirements.
The compliance of
harmed
by
industry
standard
wave
soldering
these connectors will be assured by purchase
processes. Cermetek recommends against exposing
specifications
and
incoming
inspection.
the non-hermetic CH1786NH to aqueous based
Documentation of such specifications and/ or
rinsing processes.
inspections will be provided to the FCC within 30
days of their request for the same.
Socketing.
The socketing approach to mounting
eliminates cleaning and desoldering concerns. When
Telephone Company Procedures. The goal of the
the socket is used, it must make a solid connection to
telephone company is to provide you with the best
all pins.
Failure to do so will cause unreliable or
service it can. In order to do this, it may occasionally
intermittent operation. Also, steps should be taken to
be necessary for them to make changes in their
assure that the module remains tightly seated in the
equipment, operations or procedures.
If theses
socket during shipping. Cermetek recommends using
changes might affect your service or the operation of
sockets from Samtec. See Application Note # 130,
your equipment, the telephone company will give you
Summary of Recommended Suppliers.
notice, in writing, to allow you to make any changes
necessary to maintain uninterrupted service.
2004 Cermetek Microelectronics, Inc.
Page 12
Document No. 607-0004 Revision L4 (08/04)
Cermetek Microelectronics, Inc.
CH1786 Family of Ultra Small 2400bps Modems
In certain circumstances, it may be necessary for the
DEFAULT STATUS, PERFORMANCE, AND
telephone company to request information from you
SPECIFICATIONS
concerning the equipment which you have connected
to your telephone line.
Upon request of the
The following is a summary of the Default
telephone company, provide the FCC registration
Configuration Profile installed by Cermetek
number and the ringer equivalence number (REN);
Microelectronics, Incorporated, prior to delivery
both of these items are listed on the equipment label.
of the CH1786.
The sum of all of the REN’s on your telephone lines
should be less than five in order to assure proper
Async mode selected
service from the telephone company. In some cases,
2400bps
a sum of five may not be useable on given line.
Bell 212A operation at 1200bps
Consult your telephone provider.
Even parity
Auto answer enabled (Disabled on CH1786NH)
If Problems Arise .
If any of your telephone
Command echo ON
equipment is not operating properly, you should
All result codes enabled –extended
immediately remove it from your telephone line, as it
Wait for dial tone before dialing =2 seconds
may cause harm to the telephone network. If the
Detects busy signal
telephone company notes a problem, they may
Full word result codes
temporarily discontinue service. When practical, they
Pulse dial make/break ratio =39/61
will notify you in advance of this disconnection. If
DSR enabled
advance notice is not feasible, you will be notified as
Modem ignores DTR
soon as possible.
DCD enabled (Disabled on CH1786NH)
When you are notified, you will be given the
Speaker enabled but off when receiving carrier
opportunity to correct the problem and informed of
Speaker volume set to medium
your right to file a complaint with the FCC. Contact
Local modem will grant RDL request from remote
your local telephone service provider if you have nay
modem
questions about your phone line.
Guard tones disabled
Minimum DTR pulse width =0.1 seconds
In the event repairs are ever needed on the (insert
Ring count =01 (CH1786)
your product name), they should be performed by
Escape code character =43
(insert your company name) or an authorized
Carriage return character =13
representative of (insert your company name). For
Line feed character =10
information contact: (insert your company address).
Back space character =08
Duration of wait for dial tone =02 seconds
Duration of wait for carrier after dialing =30 seconds
Duration of dial pulse (comma)=02 seconds
Carrier detect response time =0.1 seconds
Escape code guard time =1 second
Length of use after comma =2.0 seconds
Last carrier to hang up delay =0.1 seconds
DTMF interdigit delay =0.1 seconds
DTMF Attenuation =-4dB
Sleep mode inactivity time =5 seconds
Long space disconnect disabled
2004 Cermetek Microelectronics, Inc.
Page 13
Document No. 607-0004 Revision L4 (08/04)
Cermetek Microelectronics, Inc.
CH1786 Family of Ultra Small 2400bps Modems
Figure 7.
PSTN Line Interface for all CH1786 Products.
1. Currently Limiting PSTN Protection Line
protection as indicated in dashed Box 4 MUST BE
Device.
included when using CH1786NH products.
Currently limiting devices are mandatory to meet
UL safety standards. To maintain conveyed FCC
4. Optional External Over Voltage and Lightning
Part 68 approval, the current limiting components
Protection.
identified as F1 and F2 in dashed Box #1 must
In most environments, the internal two terminal
also survive FCC Part 68 surge testing. Refer to
surge suppressor (see dashed Box 3) is adequate.
Cermetek Application Note #126, Supplemental
For severe environments, use an external three
PSTN Line Protection, for more details. Refer to
terminal device with an earth ground as is shown
Application Note # 130, Summary of Recommend
in dashed Box 4.
Suppliers, for a list of suppliers and associated
part numbers.
5. EMI/RFI Suppression.
EMI/RFI suppression is recommended. This is for
A resettable/repairable fuse (rated at 0.15 amps)
obtaining FCC part 15 A and/or B. It is also used
is preferred because it resets automatically upon
to suppress external EMI / RFI signals that can
removal of the current flow.
Non-resettable
affect modem operation, such as strong radio
devices are also acceptable. Although CSA CS-
signals, should the modem be near a source of
03 Part 1 (Canada) follows the requirements of
such signals.
No external EMI/RFI noise
FCC Part 68 (USA), Cermetek recommends
suppression circuitry is required to maintain
contacting DOT (Canada) and/or a certified
conveyed FCC Part 68 approval.
Additional
independent lab to verify compliance.
suppression may be added as described below
without adversely affecting FCC Part 68 approval.
2. PSTN Current Limiting Resistors.
Low value (10 Ω ) carbon film 1/4 watt resistors may
A. To provide adequate EMI/RFI suppression,
be required (identified as R1 and R2 in dashed
the capacitor/inductor network contained in
Box 2), depending on end product application
dashed Box 5 should be located as close to
environment, to enhance performance by reducing
the RJ-11C Jack as possible.
Further, this
susceptibility to PSTN current surges that may
network should be provided with an excellent
occur before the OVERVOLTAGE PROTECTION
ground path to the chassis.
device (identified as D1 in dashed Box 3)
B. Capacitors C1 and C2 should not exceed
becomes fully activated.
0.005 µ f. They must have a rating of 1.5KV
and typically are 0.001 µ f ± 20%. Inductors L1
Refer to Cermetek Application Note # 130,
and L2 may be either individual inductors or a
Summary of Recommended Supplies, for a list of
dual inductor. Refer to Application Note #130
suppliers.
for a complete list of recommended vendors
and associated part numbers.
For UL
3. Over Voltage and Lightning Protection.
applications, choose capacitors and inductors
Surge Protection is provided by internal circuitry
that are UL 1950 listed. The actual values of
contained within all CH1786s (except CH1786NH).
the components used may vary depending on
No additional external components are required to
the end product design and the nature of the
maintain conveyed FCC Part 68 approval for all
EMI/ RFI. Consult an FCC part 15 consultant
CH1786s Products (except CH1786NH). External
if required.
2004 Cermetek Microelectronics, Inc.
Page 14
Document No. 607-0004 Revision L4 (08/04)
Cermetek Microelectronics, Inc.
CH1786 Family of Ultra Small 2400bps Modems
Table 7. CH1786 System Data Mode Compatibility Specifications.
Parameter
Specification
Parameter
Specification
Asynchronous
2400, 1200 600 bps character
Receive Carrier
Originate 2400Hz ± 7Hz
asynchronous.
Frequencies
Answer
1200Hz ± 7Hz
0-300 bps asynchronous
V.22 bis, V.22,
212A
Asynchronous
Speed
TXD may differ +1%, -2.5%
Bell 103
Answer
‘space’ 2020Hz ±
Range
from modem output. Offsets
7Hz
will be corrected by adding/
Answer
‘mark’
2225Hz ±
deleting stop bits.
7Hz
Originate ’space’
1070Hz ±
7Hz
Originate ‘mark’
1270Hz ±
7Hz
Asynchronous Format
8,9,10 bits, including start,
Receiver
OFF to ON threshold –43 dBm
stop, parity.
Sensitivity
ON to OFF threshold –48 dBm
Telephone Line Interface
Two-wire
full
duplex
over
Billing Delay
2.0 to 3.0 seconds (T a =25°C)
public switched network. On-
chip hybrid and billing delay
timers.
Modulation
V.22 bis, 16 point QAM at 600
Hysteresis
2 dB minimum
baud. V.22 and 212A, 4 point
DPSK at 600 baud.
103
Binary phase coherent FSK.
Self
Test
Pattern
Alternate ‘ones’ and ‘zeros’
Line
Fixed
compromise
Generator
and error detector, to be used
Equalization
equalization,
transmit.
along with most loopbacks. A
Adaptive
equalizer
for
number
indicating
the
bit
PSK/QAM, receive.
errors detected is sent to DTE.
Transmit
Carrier
Originate 1200Hz ± .01%
Diagnostic
Local analog loopback.
Frequencies V.22 bis,
Answer
2400Hz ± .01%
Available
Local analog loopback.
V.22, 212A
Remote digital loopback.
Request
remote
digital
loopback.
Local
interface
loopback
modem with self-test.
Bell 103
Originate ’space’
1070Hz ±
Call Progress
With speaker or quiet screen
.01%
Tones Detected
messages (No dial tone, busy,
Originate ‘mark’
1270Hz ±
ring-back, modem answer tone
.01%
and voice).
Answer
‘space’ 2020Hz ±
Computer
IBX PC/XT/AT bus compatible
.01%
Interface
with an 8250/16450/16550A
Answer
‘mark’
2225Hz ±
UART as a serial controller.
.01%
2004 Cermetek Microelectronics, Inc.
Page 15
Document No. 607-0004 Revision L4 (08/04)
Cermetek Microelectronics, Inc.
CH1786 Family of Ultra Small 2400bps Modems
Table 8. CH1786 Electrical Specifications.
Parameter
Description
Min.
Typ.
Max.
Units
V CC
Positive Supply Voltage- Noise less than 50mV
4.75
5.0
5.25
V
I CC Off Hook
Nominal Operating Current when modem is OFF Hook
50
75
mA
I CC On Hook
Nominal Operating Current when modem is ON Hook
25
50
mA
I CCPD
Power Down Current
10
mA
V IH
High Level Input Voltage*
2
V
V IL
Low Level Input Voltage*
-0.3
0.8
V
I IN
Input Leakage Current (TXD, DTR, RTS)
15
100
uA
I LO
Leakage Current DCD, HS, RXD, SLEEP, DSR
10
uA
C P
Capacitive Lead (TXT, DTR, RST)
10
pF
VT+
Positive Hysteresis Threshold for RESET pin
2.5
V
VT-
Negative Hysteresis Threshold for RESET pin
1.8
V
V OH
High Level (I OH = 0.5mA)*
2.4
V
V OL
Low Level (I OL = 1.6mA)*
0.6
V
Test conditions: VCC = 5V ± 10%, Temp = 0 ° C to 70 ° F (unless otherwise stated).
*Output Load = 50 pF ± one TTL.
Table 9. CH1786 Electrical Specifications.
Parameter
Minimum
Typical
Maximum
Units
Comments
Off Hook Impedance
20
Ohms
Trans Hybrid Loss
25
dB
600 Ohm, RXA, TXA
Ring Voltage Loop
75V
250V
V pp
On 48VDC line voltage for
sustained periods
Line Loop Current-(Off-
20
100
mA
Hook)
Return Loss @ 1000Hz
15
dB
600 Ohm
Ring Frequencies
40
Hz
Receiver Insertion Gain
-0.5
0.0
+0.5
dBm
600 Ohm- Data Mode
Transmit Power
-9.5
dB
First Character After Reset
0.5
1.0
5
sec
Delay
Inter Character Delay
20
50
msec
Between all command
characters
Command Delay
100
200
msec
Between all AT commands
Minimum Reset Pulse
10
msec
If user supplied
Duration
2004 Cermetek Microelectronics, Inc.
Page 16
Document No. 607-0004 Revision L4 (08/04)
Cermetek Microelectronics, Inc.
CH1786 Family of Ultra Small 2400bps Modems
Table 10. Other Performance Specifications.
Parameter
Minimum
Typical
Maximum
Units
Comments
Tone 2 Harmonic
nd
-35
dB
HYB enabled into 600 Ω
Distortion
DTMF Twist (Balance)
3
dB
DTMF Tone Duration
50
255
ms
95ms default
Pulse Dialing Rate
8
10
20
pps
10pps default
Pulse Dialing Make/
39/61
%
US, Canada default
Break
Pulse Dialing Make/
33/67
%
UK, Hong Kong
Break
Pulse Interdigit
700
3000
ms
789ms default
Interval
Guard Tone
550
Hz
Referenced to High Channel
Frequency
Transmit
Guard Tone Amplitude
-6
dB
Referenced to High Channel
Transmit
Guard Tone
1800
Hz
Referenced to High Channel
Frequency
Transmit
Guard Tone Amplitude
-9
dB
Referenced to High Channel
Transmit
High Channel
-1
dB
Referenced to Low channel,
Transmit Amplitude
Guard tone enabled
nd
Guard Tone 2
-40
dB
Harmonic Distortion
Call Progress
120
620
Hz
Passband Frequency
Wait Time for Dial tone
2
255
sec
Two second default
Return loss @ 1000Hz
30
dB
T r =600 Ω + 2.16 µF
Table 11. Analog Characteristics.
Name
Type
Characteristic
Value
SPK
O(DF)
Minimum Load
300 Ω
Maximum Capacitive
0.01µ
Load
10 Ω
Output Impedance
2.5± 1.6V
Output voltage
<20mV
D.C. Offset
2004 Cermetek Microelectronics, Inc.
Page 17
Document No. 607-0004 Revision L4 (08/04)
Cermetek Microelectronics, Inc.
CH1786 Family of Ultra Small 2400bps Modems
Table 12. CH1786 Pin Functions.
PACKAGE CONNECTION TABLE
PIN NO.
FUNCTION
PIN NO.
FUNCTION
1
RING
12
V/D
2
TIP
13
DTR
3
RXA
14
DSR
4
TXA
15
RI
5
SPK
16
CTS
6
NC
17
DCD
7
NC
18
HS
8
SLEEP
19
VCC
9
NC
20
GND
10
TXD
21
RST
11
RXD
22
NC
Figure 8.
CH1786 Physical Dimensions.
2004 Cermetek Microelectronics, Inc.
Page 18
Document No. 607-0004 Revision L4 (08/04)
Cermetek Microelectronics, Inc.
CH1786 Family of Ultra Small 2400bps Modems
Table 13. Summary CH1786 Family of Products.
Operating
Model
Summary of Features
Temperature
CH1786
Full function, Voice/Inject, NVRAM, FCC Part 68 approved, UL 1950
0°C to 70°C
Listed, Hermetic
CH1786ET
Full function, Voice/Inject, NVRAM, Zero Power Option, FCC Part 68
-40°C to 85°C
Approved, UL 1950 Listed, Hermetic
CH1786FX
Full function, FAX, Voice/Inject, NVRAM, FCC Part 68 approved, UL
0°C to 70°C
1950 Listed, Hermetic
CH1786LC
Full function, Voice/Inject, FCC Part 68 Approved, UL 1950 Listed,
0°C to 70°C
Hermetic
CH1786NH
Full function, FCC Part 68 Approved, Non-Hermetic, Listed UL 1950
0°C to 70°C
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.
Cermetek provides the user with a FCC/DOT Approved or Approvable device. However Cermetek does not have influence or
knowledge of Application environment.
Therefore, for FCC Approved or Approvable devices, the user assumes all risk for
maintaining compliance to registration.
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: sales@cermetek.com
iModem Network WEB SITE: http://www.imodem.net/ or https://sunnyvale.imodem.net/
2004 Cermetek Microelectronics, Inc.
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Document No. 607-0004 Revision L4 (08/04)