CH1794 Cermetek Microelectronics, CH1794 Datasheet - Page 9

• Manufacturer Part Number: CH1794
• Manufacturer: Cermetek Microelectronics

Specifications of CH1794

• Lead Free Status / RoHS Status: Supplier Unconfirmed

Cermetek Microelectronics, Inc.
AT COMMAND APPLICATIONS
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.
Example:
Enter:
In response to this command, the HS Modem 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 HS Modem automatically releases the
line and sends a NO CARRIER result code.
carrier is detected, the HS Modem gives a CONNECT
result
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 a 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 commands the modem to pause for
a specific length of time. The factory default pause
time is 2 seconds.
Example:
Enter:
Result:
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.
specify which type to use, the modem defaults to the
type last specified. The power-on default value is T.
Example:
Enter:
Result:
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.
modem with an independent DTMF tone generator.
2004 Cermetek Microelectronics, Inc.
code
Dial Number.
ATD1234567<CR>
Dial 9, pause, dial number.
ATDT9, T1234567<CR>
OK<CR><LF>
Pulse dial 9, pause, touch-tone dial
number.
ATDP9, T1234567<CR>
OK<CR><LF>
and
If the dial command does not
This is useful when using the
goes
Inserting a comma in the
on-line,
If no carrier is
permitting
If a
Page 9
Example:
Enter:
Result:
Automatic Answering.
S0=0*
S0=1-254 ANSWER ON RING 1 TO RING 254
S0=255
*When S0 is set to 0, the modem will not auto-answer.
PHONE LINE CONNECTION GUIDELINES
1.
2.
3.
4.
5.
6.
7.
8.
9.
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 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).
Connection to phone line should be made
through an RJ-11C jack.
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.
have a nominal width of 0.020 inches or greater.
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.
No additional circuitry other than that shown in
Figure 7 may be connected between the modem
module and the RJ-11C jack.
invalidate the FCC approval.
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.
The supplied FCC registration label must be
applied visibly on the outside of the product.
The product’s User Manual must provide the user
with instructions for connection and use as
recommended in the FCC Registration Section
below.
Touch-tone dial 9, pause, go off-hook,
return for additional AT commands.
ATDT9, T;<CR>
OK<CR><LF>
DO NOT ANSWER TELEPHONE
ANSWER ON RING 255
Document No. 607-0003 Revision K6 (08/04)
High Speed Modem and FAX Family
The traces should
Doing so will