ch1786nh ETC-unknow, ch1786nh Datasheet - Page 9

• Manufacturer Part Number: ch1786nh
• Description: Ch1786 Family Ultra Small 2400bps Modems
• Manufacturer: ETC-unknow

Cermetek Microelectronics, Inc.
Result:
In response to this command, the CH1786 dials the
telephone number “123-4567” and then waits for a
carrier from the distant modem.
detected within a given time (the default time is 30
seconds), the CH1786 automatically releases the line
and sends a NO CARRIER result code. If a carrier is
detected, the CH1786 gives a CONNECT result code
and goes on-line, permitting communication with the
distant modem.
The Dial Command may also be issued without a
telephone number. ATD causes the modem to pick
up the telephone line without dialing a number.
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.
telephone number instructs the modem to pause for a
specific length of time. The factory set default pause
time is 2 seconds.
Example: Dial 9,pause, dial number.
Enter:
Result:
Multiple commas may be used to generate integer
multiples of the specified delay time.
Originate a Call in Answer Mode. The D command
forces the modem into originate mode. To call an
originate-only modem, dial the number and set the
modem to answer mode via the R command (reverse
originate). This is done by including an R at the end
of the telephone number.
Example: Change
Enter:
Result:
Multiple commas may be used to generate integer
multiples of the specified delay time.
Redial Last Number.
convenient way to execute the previously entered
command line.
Example: Use A/, the repeat command, to redial the
last telephone number dialed.
Enter:
Result:
Return to Command State.
command mode offer dialing.
Example: Touch-tone dial 9, pause, dial number,
return to Command.
2003 Cermetek Microelectronics, Inc.
ATDT9,1234567<CR>
OK
answer mode.
ATDT1234567R<CR>
OK
A/
ATDT1234567R<CR> Previous command
OK
OK
modem
The repeat command is a
Inserting a comma in the
from
line executed
Use ; to return to
original-only
If no carrier is
to
Page 9
Enter:
Result:
Automatic Answering. The SO register controls the
number of rings that must occur before the modem
answers a call. The register may range in value from
0 to 255.
S0 =
S0 =
S0 =
S0 =
S0 =
When S0 is set to 0,the modem will not auto-answer.
The Serial Interface Lines. The CH1786 supports a
full EIA-232D/V.24 serial interface. Signal levels are
TTL rather than EIA-232D level compatible, which
allows direct connection of the CH1786 to the host
UART without the need for level translation circuitry.
See Table 2 for a complete pin description.
The CH1786 is controlled by sending it serial
commands over TXD and it’s status determined by
monitoring the serial status messages returned on
RXD. DTR is optionally used to reset, terminate calls
or return CH1786 to command mode.
All other serial interface lines may be utilized for the
convenience of a particular application but are not
required by the CH1786.
modem) should be left unconnected. Unused inputs
should be set to the proper logic level. See Table 2.
Fax Modes. The CH1786 Product Family supports
Send and Receive FAX. The modes and rates are
determined by the AT+F commands. Refer to Table
6A.
FAX modem processing is explicitly defined in
CCITTV.29,
recommendations.
spectrum, and data processing functions conform to
the appropriate specifications.
Register
S0*
S1
S2
S3
S4
S5
S6
S7
S8
Table 4. CH1786 Register Summary.
0 DO NOT ANSWER TELEPHONE
1 ANSWER ON RING 1
2 ANSWER ON RING 2
3 ANSWER ON RING 3
255 ANSWER ON RING 255
ATDT9,1234567;<CR>
OK
CH1786 Family of Ultra Small 2400bps Modems
Function
Ring to Answer On
Ring Count
Escape Code Character
Carriage Return Character
Line Feed Character
Back Space Character
Wait for Dial tone
Wait for Data Carrier
Pause Time for Comma
CCITTV.27,
Document No. 607-0004 Revision L1 (06/03)
All
modulation,
Unused outputs (from
and
CCITT
wave-form
V.21