User manual

Section 3
BEFORE YOU START
Copyright (C) Dataplex Pty Ltd
3-1
3.0 BEFORE YOU START
The DPX-213 is a combined soft-strapped and link selectable modem. There are number of
internal links which can be used to select Async/Sync operation, DTR wakeup and LED
operation. All other parameters are set by software commands from an attached
asynchronous terminal and then stored in Non Volatile Random Access Memory
(NVRAM). These setups or configurations are stored in 'S-registers'.
3.1 Command Structure
In general, commands entered into the modem are prefixed with 'AT' and end with a
carriage return (
K
). The modem automatically determines the terminal speed and
parity from the AT characters, loads the command into a buffer as you type it, and executes
the command when you hit the carriage return.
The factory defaults assume you are going to use the modem for asynchronous operation
on the dial network at the fastest speed the line or modem can accommodate. The character
format is assumed to be 10 bit ASCII, consisting of 1 start bit, 8 data bits and 1 or more
stop bits. For 8 to 11 bit configurations, read Section 5 on Applications and Section 8 on S-
Registers.
3.2 Communications Software
The software used to configure the DPX-213 can range from simple dumb terminal
emulators to advanced communications systems. The DPX-213 is compatible with
virtually all communications software packages. If using a smart communications package,
ensure it supports the AT command set. Most packages also send an initialisation string.
This should be checked for correctness before using the modem.
3.3 Manual and Automatic Calling
Calls can be initiated by raising DTR from the terminal and typing an AT command string.
Calls can be answered by the same methods.