Specifications

Cascade Modem Manual

Page 10

Boot Command Sequence

Command

Description

AT:M0000,42,4F,4F,54,0D,41,54,45

Load characters “B,O,O,T,<CR>,A,T,E” in EEPROM beginning at

address M0000

AT:M0008,30,0D,41,54,51,31,0D,41

Load characters “0,<CR>,A,T,Q,1,<CR>,A” in EEPROM beginning at

address M0008

AT:M0010,54,53,30,3D,31,0D,0D,0D

Load characters “T,S,0,=,1,<CR>,<CR>,<CR>” in EEPROM beginning at

address M0010

2.6. DAA-Telephone Line Interface

High performance modems are extremely sensitive to the DAA (Data Access Arrangement) performance. The

difference between a good modem and a fair one is in the DAA performance.

The Cascade Modem includes a specially designed low distortion DAA to achieve optimal performance over all

telephone line conditions, achieving the most reliable and best performance telephone connections.

The Cascade Modem is designed to meet North American telephone standards as set by FCC Part 68 and DOC. The

telephone line interface is designed to meet 1000 VAC and 1500 volt peak surge isolation, among other

parameters. As such it will meet U.S. and Canadian requirements and other international requirements that specify

that level of isolation.

The Cascade Modem connection to the telephone network is through a RJ11 jack using the standard Tip and Ring.

These two telephone line connections must be routed to an external network for improved field reliability in

hostile environments, for Canadian approval, for UL compliance, and also optionally for FCC Part 15 compliance if

required.

2.7. Modem States

The modem can be in either a command mode or a data mode. When the modem is idle, it is in the command state.

When a data call is in progress it is in the data mode state. The modem does not recognize commands when in the

data mode.

To recognize commands the computer must send an “escape sequence” to the modem that forces it out of the data

mode and into the command mode. The escape sequence consists of a “guard time” (a period where no characters

are sent to the modem), followed by 3 escape characters, followed by a “guard time” again.

At power up the guard time is set to 1 second minimum and the escape character is set as “+”. These two

parameters can be modified via registers S2 and S12. The modem will stay off-hook with its carrier on after the

escape sequence is received. It returns an OK status message when it is ready to accept commands. You may

reenter the data mode by issuing the ONLINE command ATO[CR].