RC56D, RC336D, and RC144D Modem Device Sets Designer’s Guide
1154
Conexant
2-1
2. TECHNICAL SPECIFICATIONS
2.1 SERIAL DTE INTERFACE OPERATION
2.1.1 Automatic Speed/Format Sensing
Command Mode and Data Modem Mode. The modem can automatically determine the speed and format of the data sent
from the DTE. The modem can sense speeds of 300, 600, 1200, 2400, 4800, 7200, 9600, 12000, 14400, 16800, 19200,
21600, 24000, 26400, 28800, 38400, 57600, 115200, and 230400 bps and the following data formats:
Parity
Data Length
(No. of Bits)
No. of
Stop Bits
Character
Length
(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 modem can speed sense data with mark or space parity and configures itself as follows:
DTE Configuration
Modem Configuration
7 mark
7 none
7 space
8 none
8 mark
8 none
8 space
8 even
Fax Modem Mode. In V.17 and V.34 fax modes, the modem can sense speeds up to 230.4 kbps.
2.2 PARALLEL HOST BUS INTERFACE OPERATION
Command Mode and Data Modem Mode. The modem can operate at rates up to 230400 bps by programming the Divisor
Latch in the parallel interface registers if supported by communications software and/or driver (a Windows 95 driver is
available from Conexant).
Fax Modem Mode. In V.17 and V.34 fax modes, the modem can operate at rates up to 230.4 kbps by programming the
Divisor Latch in the parallel interface registers if supported by communications software and/or driver (a Windows 95 driver is
available from Conexant).
2.3 ESTABLISHING DATA MODEM CONNECTIONS
Telephone Number Directory
The modem supports four telephone number entries in a directory that can be saved in a serial NVRAM. Each telephone
number can be up to 32 characters in length. A telephone number can be saved using the &Zn=x command, and a saved
telephone number can be dialed using the DS=n command.
Dialing
DTMF Dialing. DTMF dialing using DTMF tone pairs is supported in accordance with ITU-T Q.23. The transmit tone level
complies with Bell Publication 47001.
Pulse Dialing. Pulse dialing is supported in accordance with EIA/TIA-496-A.
Blind Dialing. The modem can blind dial in the absence of a dial tone if enabled by the X0, X1, or X3 command.
Modem Handshaking Protocol
If a tone is not detected within the time specified in the S7 register after the last digit is dialed, the modem aborts the call
attempt.
Summary of Contents for RC144D
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