CH1788 Cermetek Microelectronics, CH1788 Datasheet - Page 10

• Manufacturer Part Number: CH1788
• Manufacturer: Cermetek Microelectronics

Specifications of CH1788

• Lead Free Status / RoHS Status: Supplier Unconfirmed

Cermetek Microelectronics, Inc.
Escape Sequence. The escape sequence consists
of a “guard time” of one second (a period where no
characters are sent to the modem), followed by 3
escape characters (typically +++), followed by
another guard time of one second.
character code is set in register S2. By default, the
escape character is set as “+.” There is no required
delay between characters.
sequence has successfully been sent, the escape
characters will not be transmitted to the remote
modem.
The CH1788 will stay Off-Hook with its carrier on after
the escape sequence is received. It will return an OK
status message on RXD when it is ready to accept
commands. The CH1788 may be put into data mode
again by issuing the command ATO.
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 the digits of the phone
number to be dialed.
Example: Dial number.
Enter:
Result:
In the above example, the CH1788 dials the
telephone number 1234567, conducts handshaking
negotiations then waits for a carrier from the distant
modem. If a carrier is not detected within the time
period specified by register S7, the CH1788 will
automatically release the PSTN line and send the
appropriate result code to the host. If a carrier is
detected, the CH1788 will send the CONNECT result
code and will permit communication with the distant
modem.
receive data after the CONNECT result code is sent
or when an active signal is present on DCD. DCD
line must be enabled with the ATC1 command.
A variety of dial modifiers can be placed in the dialing
string to make it application specific. These include
pause, hook flash, pulse dialing, wait for dial tone,
etc. See the detailed D command.
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.
Programmable S-Registers. The CH1788 contains
a variety of registers that store the configuration and
personality parameters for the CH1788. Both default
configuration
parameters are stored.
Registers is given in Table 4. A detailed description
of each is available in CH1788 Command and S-
2006 Cermetek Microelectronics, Inc.
Note, the CH1788 is ready to send and
ATD1234567<CR>
OK
and
user
A summary of the S-
specified
When the escape
configuration
The escape
Page 10
Register Reference Guide. Do not attempt to modify
S-Registers that are not listed in the table.
Automatic Answering.
number of rings that the CH1788 must detect before it
will answer. S0 may range in value from 0 to 255.
S0 =0 DO NOT ANSWER TELEPHONE
S0 =1 ANSWER ON RING 1
S0 =2 ANSWER ON RING 2
S0 =3 ANSWER ON RING 3
S0 =255 ANSWER ON RING 255
When S0 is set to 0, the modem will not answer.
Register
S110
S111
S10
S11
S13
S17
S18
S23
S30
S31
S51
S52
S53
S54
S55
S56
S57
S58
S65
S66
S67
S68
S69
S86
S89
S95
S0*
S1
S2
S3
S4
S5
S6
S7
S8
S9
Table 4.
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
Carrier Detect Response Time
Lost Carrier to Hang-up Delay
DTMF Tone On/Off
DTMF Data/ Transmit Attenuation
Ring Minimum Frequency
Ring Maximum Frequency
Call Progress Functions
Data Modulation Selection
Data Modulation Status
Ring/ Cadence A minimum On-Time
Ring/ Cadence A maximum On-Time
Ring/ Cadence A minimum Off-Time
Ring/ Cadence A maximum Off-Time
Ring/ Cadence B minimum On-Time
Ring/ Cadence B maximum On-Time
Ring/ Cadence B minimum Off-Time
Ring/ Cadence B maximum Off-Time
DTMF Detection
Wait For Dial Tone Timer
Minimum Duration Of Dial Tone
Test Timer
Test Error Count
Hook Flash On Time
Fast Connect/Pickup
Caller ID configuration
Line-In-Use/ Parallel Pick-Up
Register
Line-In-Use Setting Time
CH1788 Surface Mount PLCC 2400bps Modem
CH1788 S-Register Summary.
Document No. 607-0018 Revision A6 (01/06)
Register S0 specifies the
Function