Cermetek CH2056 Manual

FEATURES
• Supports V.90, V.34bis, V.34, V.32bis, V.32, V.22bis,
V.22A/B, V.23, V.21, Bell 212A and 103
• CH2056 supports V.80 Synchronous operation
• Error correcting: V.42 LAMP, MNP 2-4 and MNP 10
• Data Compression: V.42bis and MNP 5
• MNP10 Data throughput enhancement for cellular
operation
• DTE serial interface with speeds up to 230.4kbps
(CH2056), 115.2kbps (CH1799/CH1798) or 57.6kbps
(CH1794)
• Automatic baud rate adaptability utilizing speed sensing,
flow control and data buffers
• Send & Receive Fax Class 1, Group 3 supported
• Serial V.24, 5 volt interface
• NVRAM directory and stored profiles
• AT Command structure, with extensions
• Built-in DAA with 1500 VAC RMS isolation 2122V peak
surge protection
• UL 1950 and CSA C22.2 950 Recognized
• Leased Line version available CH1799LL
• FCC part 68 Approved/DOT CSA CS-03 Part I
Approveable
• +5 Volt operation with zero power option
• Small size: 1.35" x 1.38" x 0.61" (nominal)
• Pin compatible with low speed/low cost CH1786
INTRODUCTION
The CH2056, CH1799, CH1798 and CH1794 (HS Modem
Family) are industrial grade high-speed modem modules.
Each HS Modem product supports a range of modem
standards and speeds
28,800bps, 33,600bps or 56,000bps.
compression algorithms the operating speed can be
expanded to the maximum DTE rate of 57.6kps for the
CH1794, 115.2Kbps for
230.4kbps for the CH2056.
schemes is available including MNP 10 for cellular
telephone applications. The HS Modem family supports
Send and Receive Fax.
exclusively on non-voltage bearing leased line.
The HS Modem family is pin compatible with Cermetek's low
cost CH1786 V.22bis, 2400bps modem family.
module in the HS Modem family is a self-contained modem
and is FCC Part 68 approved and Canadian DOT
approveable. These ultra small modules are designed for
PCB through-hole mounting and are 1.35" x 1.38" x 0.58" in
size. The HS Modem family requires only two external
interfaces: a CCITT V.24 serial interface that can be routed
directly to a UART, and a Tip and Ring interface which goes
directly to an RJ-11C Jack for the PSTN line connection.
The HS Modem can be controlled with industry standard AT
commands and is compatible with available industry
communication software.
DESCRIPTION OF FUNCTIONAL BLOCKS AND
DISCUSSION OF BASIC OPERATIONS
2001 Cermetek Microelectronics, Inc.
HIGH SPEED Modem and FAX FAMILY
CH2056
CH1799
CH1798
CH1794
from 300bps to 14,400bps,
By using built in
the CH1798/CH1799
A choice of error correcting
The CH1799LL operates
Each
– V.90 / 56,000bps
– V.34bis / 33,600bps
– V.34 / 28,800bps
– V.32bis / 14,400bps
Figure 1 contains a functional block drawing of the HS
Modem family of products.
consists of a serial interface buffer, modulator/demodulator,
modem controller with error correction and data compression,
non-volatile RAM and a DAA.
Figure 1. Function Block Diagram of HS Modem Family.
MODEM
CONTROL
SERIAL V.24
INTERFACE
SERIAL
INTERFACE
AND BUFFER
Serial Host Interface Buffer.
The HS Modem utilizes a serial V.24 EIA 232-E 5V interface
to control the modem.
communicate over the serial interface with the Data Terminal
Equipment (DTE) at a fixed speed regardless of the carrier
line modulation speed (DCE) of the PSTN modem
connection. This eliminates the need to have the DTE step
up or step down in speed based on the incoming or out-going
PSTN communication data rate. Hence, the DTE can train
the CH2056, to say 56kbps, and talk to a slower incoming
and
data connection at say, 2400bps without changing host
speed. Conversely, the host DTE trained at 14.4kbps can
also communicate with the modems at higher speeds, say
28.8kbps. This is accomplished by invoking internal
automatic data flow control. The HS Modem family has a
resident buffer to allow for this auto baud operation.
Non-Volatile RAM (NVRAM).
NVRAM can store two user-customized configurations. The
AT&Wn command will store the active modem configuration
in one of two NVRAM locations as selected by an n of 0 or 1.
The AT&Yn command selects one of the stored modem
configurations to be automatically recalled and made active
upon reset or power up. The ATZn command immediately
recalls and activates a stored configuration. See Tables 7A
and 7B for storable S-Registers and Commands.
The NVRAM can save up to four telephone numbers, with up
to 31 digits or modifiers in each telephone number.
AT&Zn=s command will store s, the telephone number dial
string. The ATDS=n command will cause the modem to dial
one of the four stored telephone numbers.
storage location for the four telephone numbers is selected
by an n of 0, 1, 2, or 3.
Page 1
Each HS Modem product
ERROR CORRECTING
DATA COMPRESSION
HS Modem
NVRAM
TELEPHONE
MODULATION
LINE
DEMODULATION
INTERFACE
GND
VOICE/TONE
SPEAKER
+5V
INTERFACE
The HS Modem products can
Document No. 607-0003 Revision I (05/01)
TIP
RING
INPUT
The
The NVRAM