Dataplex DPX-213 User Manual

DPX-213

LOW POWER DATA MODEM

USER MANUAL

2400/1200/300bps MNP-5 Data

Leased Line & Dial Network Modem

Document No 113-213-

01 Rev 1.0

WARNING

When operating the DPX213 from a DC supply ensure that any devices that are connected to the DPX213 have a common NEGATIVE ground or are powered from an isolated source. It is recommended that the supply be connected via a disconnection device or an over-current protection device.

SAFETY

The 48V free standing unit is fitted with a 2m power supply cable with bare wire ends. This power supply cable must be connected to the power source via a disconnection device or an over-current protection device. A circuit breaker rated 1A, 100 VDC will satisfy both requirements. Observe correct polarity:

•

Red wire to positive;

•

Black wire to negative.

This manual is copyrighted © 1994 by Dataplex Pty. Ltd. with all rights reserved. This manual cannot be reproduced in any form without the prior written consent of Dataplex Pty. Ltd. No patent liability is assumed with respect to the use of the information contained in this manual.

TRADEMARKS

DPX-213 is a trademark of Dataplex Pty. Ltd. DATAPLEX is a trademark of Dataplex Pty. Ltd.

Document No 113-213-01 Rev 1.0 2008

III

CONTENTS

1.0 INTRODUCTION 1-1

1.1 Features of the DPX-213 1-1

1.2 Requirements 1-1

1.3 About the Manual 1-2

1.4 The DPX-213 Modem 1-3

2.0 INSTALLATION 2-1

2.1 Setting the Internal Jumpers 2-1

2.2 Connecting the DPX-213 to the Telephone Line 2-2

2.3 Connecting a Terminal or Computer to the DPX-213 2-3

2.4 Front Panel Indicators 2-3

2.5 Testing Your Connections 2-4

2.6 Setting Your PC for Speed and Character Format 2-4

2.7 Making a Connection 2-5

2.8 Closing a Connection 2-6

2.9 Call Establishment Sequence 2-6

2.10 Trouble Shooting 2-7

3.0 BEFORE YOU START 3-1

3.1 Command Structure 3-1

3.2 Communications Software 3-1

3.3 Manual and Automatic Calling 3-1

3.4 Dial-up Line and Leased Line Support 3-2

3.5 Speed Matching 3-2

3.6 Flow Control 3-2

3.7 Escape Sequence 3-3

3.8 Advanced Features 3-3

4.0 COMMAND SET 4-1

4.1 Command Line and Command Entry 4-1

4.2 Attention Code Syntax 4-2

4.3 DPX-213 Operating States 4-3

4.4 AT Command Set 4-6

Document No 113-213-

01 Rev 1.0 2008

CONTENTS

5.0 APPLICATIONS 5-1

5.1 Resetting the Modem 5-1

5.2 Operating Modes 5-1

5.3 Asynchronous Modes 5-2

5.4 Synchronous Modes 5-3

5.5 Leased Line Operation 5-4

5.6 Extended Character Formats 5-5

5.7 PABX Operating Problems 5-5

5.8 Low Power/Standby Mode 5-6

5.9 Alarm Mode 5-6

5.10 Password Mode 5-6

5.11 Remote Configuration 5-7

6.0 DATA TRANSFER 6-1

6.1 Error Control 6-1

6.2 Flow Control 6-2

6.3 Flow Control Buffers 6-2

6.4 Microcom Networking Protocol 6-4

6.5 Error Free or Not At All 6-5

6.6 Constant Speed Interface 6-5

6.7 File Transfer Restrictions 6-5

6.8 Software Compatibility 6-6

7.0 TESTING AND DIAGNOSTICS 7-1

7.1 Operator Initiated Tests 7-1

7.2 Local Analog Loopback (ALB) 7-2

7.3 Remote Loopback Response 7-2

7.4 Remote Digital Loopback (RDLB) 7-3

8.0 S-REGISTERS 8-1

9.0 TECHNICAL SPECIFICATIONS 9-1

Models Available

10.0 WARRANTY AND REPAIRS 10-1

Warranty Information Installation and Service Record

Document No 113-213-01 Rev 1.0 2008

CONTENTS

APPENDICES

Appendix A Problem Report Sheet Appendix B S Register Summary Appendix C ASCII Conversion Table Appendix D Interface Connections Appendix E AT Command Set Summary

FIGURES

Figure 2.1 Rear Panel Layout 2-1 Figure 2.2 DPX-213 Jumper Locations 2-2 Figure 2.3 Front Panel Layout 2-3 Figure 5.1 Telecom 604 Plug 5-5 Figure 6.1 Flow Control Buffers 6-2 Figure 7.1 Local Analog Loopback 7-2 Figure 7.2 Remote Digital Loopback 7-3 Figure D.1 RJ-11 Connector Wiring D-1

TABLES

Table 2.1 Front Panel Indicator Names and Functions 2-3 Table 2.2 Valid Character Formats 2-4 Table 4.1 CCITT and Bell Selection 4-7 Table 4.2 Response Codes 4-14 Table 5.1 Mode 0 Asynchronous 5-2 Table 5.2 Mode 1 Asynchronous 5-2 Table 5.3 Mode 2 Synchronous 5-3 Table 8.1 Table for Converting 8 Bit Binary to Decimal 8-1 Table D.1 V.24 Interface Connectors D-2

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Section 1

INTRODUCTION

1-1

1.0 INTRODUCTION

Welcome to the Dataplex DPX-213. Whether you are familiar with dial network modems or not, you will find the DPX-213 simple to operate. The modem offers advanced features only found in quality high-end products and opens the door to a new world of data communications. Congratulations on your purchase of the DPX-213.

1.1 Features of the DPX-213

This low power dial network and leased line data modem is designed for advanced business and professional applications. A wide range of useful features allow many different types of networks to be configured with the one compact unit. MNP 4 error correction and MNP 5 data compression permit error free transmission of data at up to four times the throughput of basic 2400 bps modems.

The DPX-213 supports five international speed standards for both synchronous and asynchronous communications.

1.2 Requirements

To operate the DPX-213, it is assumed that the user is reasonably familiar with data communications concepts and personal computers. If you are unfamiliar with data communications or personal computers, please refer to the relevant texts or user manuals. Before you can operate the modem, ensure you have the following equipment:

1. An asynchronous terminal. This can be a personal computer with an RS-232 serial port or a dumb asynchronous terminal. Once configured, synchronous devices may be used.

2. Data communications software.

3. A DTE (Data Terminating Equipment) cable.

INTRODUCTION

Section 1

1-2

1.3 About the Manual

The manual is organised to explain increasingly more advanced operations. Novice users should read all sections, in particular, Section 3 on modem basics and Section 7 on Applications. The manual is divided into 12 sections as follows:

Section 1 Introduction describes the DPX-213 features and explains how to use this

manual.

Section 2 Installation explains the purpose of each indicator, switch and connector

plus how to connect your modem to the computer and telephone line.

Section 3 Before You Start covers the command method, dialling, answering,

matching dissimilar speeds, leased line and dial network operation.

Section 4 Command Set is probably the most important Section. It explains in detail

the function of each AT command for both fax and normal modem operation.

Section 5 Applications offers some quick start information on a range of common

uses including password security, synchronous support, leased line operation, extended character set support and remote configuration.

Section 6 Data Transfer describes advanced features such as error correction, data

compression, flow control and speed matching. This Section also gives some warnings on set-up conflicts to be avoided.

Section 7 Testing and Diagnostics covers the loopbacks and test patterns available to

help isolate any problem in your cable, modem or phone line.

Section 8 S-Registers covers the software registers used to store the DPX-213

configuration options. Instructions are given to enable reading and altering the S-Register values.

Section 9 Technical Specifications gives the performance specifications of the DPX-

213 and lists the other models available.

Section 10 Warranty and Repair allows you to record the installation configuration.

Also included is warranty information and a field service request form.

Appendices The appendices contain a problem report sheet, interface signal

leads/connections information, an ASCII code table (in decimal, binary and hex), an S-registers summary table and the AT Command Set Summary.

Section 1

INTRODUCTION

1-3

1.4 The DPX-213 Modem

The DPX-213 is designed and built in Australia and offers:

•

Low Power: Standby current < 100uA.

Operating current < 100mA

•

Wake up on DTE RxD, Ring or Raise of

DTR.

•

Led operation link selectable.

•

DTR wake-up link selectable.

•

Alarm/Dialback function.

•

Password security/dialback.

•

Remote configuration.

•

Async/Sync link selectable.

•

Power from DB25, IDC or Power

Connector.

•

Small size.

•

MNP error correction & data compression.

•

Constant speed interface from 300 to 9,600

bps.

•

Automatic terminal speed detection from

300 to 9,600 bps.

•

Data operation at 300, 1200, and 2400 bps.

•

Auto-ranging on originate and answer at

300, 1200 and 2400 bps.

•

CCITT standards V.21, V.22, and V.22bis.

•

Bell 103 and Bell 212 support.

•

A rugged plastic case.

•

Front panel indicators.

•

Stored number dialling for up to ten

numbers.

•

DTR raise and AT command dialling.

•

Help screens for configuration, S-registers

and AT prompts.

•

Manufactured to ISO-9002/AS-3902 quality

standards.

•

Austel approved.

•

RFI compliant to AS-3458 and CISPR-22

class A.

INTRODUCTION

Section 1

1-4

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Section 2

INSTALLATION

2-1

2.0 INSTALLATION

Read this Section in order to correctly install your modem. It includes information on connector pinouts, front and rear panel details and a simple test of your setup.

Before operation is possible, the modem must be setup, either to the factory defaults or with special S-register values to suit your own configuration.

Most communications software packages issue a default command string to set up the modem. Before altering this default setup, check the software operations manual and Section 4, Command Set.

Figure 2.1 Rear Panel Layout

The rear panel of the DPX-213 has a single RJ-11 connector for line, together with a 25 Pin V.24/28 DCE connector. The supplied line cord connects from the RJ-11 of the DPX- 213 to the telephone wall socket. A description of the RJ-11 connectors is given in Appendix D.

2.1 Setting the Internal Jumpers

The DPX-213 contains a number of internal jumpers which have to be set before operation. The figure over page shows the location of the various jumpers.

INSTALLATION

Section 2

2-2

RESET

Figure 2.2 DPX-213 Jumper Locations

J4: Removing this jumper reduces current consumption by disabling the front panel LEDs.

J5: Removing this jumper stops the V.24 DTR input which controls the standby mode of the DPX-213. Without this jumper set, the unit will not wake up on raise of DTR and will not be held active by the DTR when the unit is placed in standby mode.

J8: This jumper enables the sync clocks on the V24 interface. When Pins 1 and 2 are shorted no sync clocks will be present at the interface. When Pins 2 and 3 are selected, both Rx and Tx sync clocks will be placed on Pins 17 and 15 of the DB25 connector.

2.2 Connecting the DPX-213 to the Telephone Line

Remove your telephone from its wall socket (you may need a flat bladed screwdriver for this) and plug one end of the supplied cable into the socket labelled "J2 LINE" on the rear of the DPX-213 and plug the other end into the wall socket. The terminal prompts will give call progress indication.

NOTE: 1. Dataplex does NOT recommend the use of double adaptors to connect your

telephone in parallel with the DPX-213. Should the handset be lifted when the modem is online, noise and errors will be injected into the data stream.

2. If the handset draws power from the telephone line (for example, to keep stored

numbers intact or to run a clock display) the battery charging current can be a source of noise and errors in the data during long modem sessions. A long data call may cause the telephone memory battery to discharge and lose the stored numbers.

Section 2

INSTALLATION

2-3

2.3 Connecting a Terminal or Computer to the DPX-213

The DPX-213 uses the industry standard 25 Pin "D" connector as its data interface, with the signals defined in the CCITT V.24, V.28 and EIA RS-232C for modems. The DPX- 213 operates as Data Circuit-terminating Equipment (DCE).

If you wish to connect the DPX-213 to a terminal or computer with a serial port configured as Data Terminal Equipment (DTE), then a "straight through" cable connecting corresponding pins of the serial ports should work. If the computer serial port is configured as a DCE, then you must use a "cross over" or "null modem" cable. Most personal computers and terminals have their serial interface configured for DTE operation. The connections needed for dumb terminals, PC's and asynchronous operation are described in Appendix D.

NOTE: When connecting the RS-232 cable to the PC, DO NOT connect the cable to the

DB25 female connector on the rear of the PC. This is the parallel port and connection may cause damage to your PC. At the PC end, the cable should be connected to a male connector (serial port) for correct operation.

The terminal cable to the modem should be less than 15 meters in length and restrained with screw locks at both ends to avoid placing too much strain on the cable. Round cable is recommended. Ribbon cables MUST be kept as short as possible to minimise clock and data interference in the ribbon.

2.4 Front Panel Indicators

The front panel of the DPX-213 contains 4 LED's (Light Emitting Diodes), which are used to indicate modem and line status.

Figure 2.3 Front Panel Layout

INSTALLATION

Section 2

2-4

Table 2.1 Front Panel Indicator Names and Functions.

Name Function Colour Status

TD Transmit Data Yellow Off for mark, On for space, flickering for data RD Receive Data Yellow Off for mark, On for space, flickering for data CD Carrier Detect Green On when CD active, Off when CD inactive.

(See AT&C command)

OH Off Hook Red On when modem is on line (Off hook). Off

when modem is off line (On-hook). When the modem is in Loop modes this LED flashes.

2.5 Testing Your Connections

With your terminal or computer connected and operating, the DTR LED should light. You can now perform a quick test to determine if you have setup the DPX-213 correctly.

After connecting your terminal or PC to the modem, power the system up and start your communications or terminal emulation package. To check that keyboard characters are reaching the DPX-213, the TD LED must flash with every keystroke.

Press the

key. Each time you press the key, the TD LED should flash briefly. If no

data is reaching the DPX-213, check that:

1. The correct COM port is being used on your PC;

2. The terminal is in the ON-LINE state and not the LOCAL Mode state, or,

3. The correct cable is being used and the cable pinouts are correct.

2.6 Setting Your PC for Speed and Character Format

The DPX-213 uses the attention request ('AT' prefix) to automatically detect terminal speeds at all standard baud rates up to 9,600 baud.

For initial configuration, the terminal used must be a ten bit ASCII device operating at one of the standard speeds, for example, 300, 1200, 2400, 4800, 9600 or 19,200 bps. The AT command processor and Constant Speed Interface accept character formats of 10 bits in total.

For example:

Section 2

INSTALLATION

2-5

Table 2.2 Valid Character Formats

Start Bit Data Bits Parity Stop Bits Total Bits

1 7 Mark 1 10 1 7 Even 1 10 1 7 Odd 1 10 1 7 Space 1 10 1 8 None 1 10

2.7 Making a Connection

Make sure the cable and terminal software are correct, then type

atK

. This allows

the modem to sense the terminal speed and calculate the parity being used. After this has been successfully decoded, the DPX-213 will reply with:

"OK"

NOTE: If the modem fails to issue the "OK" response, and you are certain the cable,

terminal speed and parity are all correct, refer to the Section on Testing and Diagnostics.

The DPX-213 comes with a default configuration suitable for many applications. As a "soft" configured product, it is possible to make errors by loading a conflicting configuration, causing unpredictable operation. If you suspect this has happened, turn the power off, wait about ten seconds, and then turn the power back on. Force the modem back to the factory default setup by typing

at&fK

Otherwise, type

ath1K

to force the modem to go Off Hook (equivalent to lifting

the handset). Typing the command line

athK

ath0K

will terminate

the call. Dial a number by typing the command line:

atd 1234567K

(Fictitious Number Only)

The above command tells the modem to dial (ATD) the number 1234567. Where nonstandard dial tones are used, such as with some PABX's, the modem may not be able to detect dial tone. In this case select the appropriate pulse or tone dialling method with the

ATDP or ATDT commands respectively and ensure the modem "blind dials" by using the ATX0 or the ATX2 command.

When dialling a number, you should see various prompts on your terminal.

INSTALLATION

Section 2

2-6

2.8 Closing a Connection

There are several ways to abort a call. If the call has been answered by a modem and both are on-line, typing any key will now send that character to the attached modem. Aborting the call in this case must be done from the on-line interactive state which is entered by typing the escape sequence of 'pause'

+++

'pause' followed by

athK

The abort timer (S-Register 7) will also abort the call if the originating modem has not established a call before S7 times out. This is normally 45 seconds but can be between 1 and 255 seconds.

Basically, a call can be terminated in several ways :

•

Hitting any key on the terminal;

•

Detection of busy tone by the DPX-213;

•

Time-out of the modem (S-Register 7);

•

Loss of carrier;

•

Typing the escape sequence ('pause'

+++

'pause') then

ath0K

Additionally, a call will be terminated when either Busy tone (engaged) is detected or loss of power is applied to the modem by switching off or removing the power cord.

NOTE: If data is present, then one of the Dumb modes should be used (AT*D2).

2.9 Call Establishment Sequence

The modem placing the call is termed the originating modem and the modem at the other end is termed the answering modem. When instructed to place a call, the originating modem will go off-hook and the OH LED will illuminate. Typically, the originating modem listens briefly for dial tone before dialling, places the call, and then listens for answer tone from the answering modem. If no tone is received within a preset time (stored in S-Register 7), the call is aborted.

The originating modem is usually silent during this initial call set-up phase, but a calling tone can be enabled (via the AT*G command) which transmits an interrupted tone so the called party can distinguish a data call from a voice call and activate the modem if required.

At the answering end, the modem detects the incoming ring, counts up to the preset number of rings (stored in S-Register 0) and then goes off-hook. It transmits an answer tone to the calling modem. Once this tone is detected by the calling modem the training sequences begins. Therefore, it usually takes a few seconds before data transfer actually begins.

Section 2

INSTALLATION

2-7

The called modem will turn on the ring indicator with each incoming ring (Pin 22). It will usually output the word "RING" to the terminal with each incoming ring unless this feature has been disabled with the ATQ or ATV commands.

The DPX-213 can be configured so it will:

•

Answer at a particular ring count (typically, the answering modem will be set

to answer on the first or second ring;

•

Never answer;

•

Answer if the data terminal ready lead (Pin 20) is asserted.

2.10 Trouble Shooting

If you are sure you have the correct cables, terminal speed and ASCII character format, but are unable to get the OK response from typing AT, the DPX-213 may have an invalid setup string stored in the NVRAM.

A Master Reset should eliminate this problem. A Master Reset will erase all stored numbers, passwords and configuration information. To initiate the Master Reset, turn the DPX-213 power off, remove the lid and short the reset pads on the PCB while turning the power back on. Wait a few seconds before removing the short

Now type

atK

as before. If you still experience problems, consult Section 7 on

Testing and Diagnostics or call your modem supplier for assistance. Details of the Warranty and Service contacts are given in Section 10.

INSTALLATION

Section 2

2-8

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Section 3

BEFORE YOU START

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 (

). 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 SRegisters.

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.

BEFORE YOU START

Section 3

3-2

3.4 Dial-up Line and Leased Line Support

The DPX-213 cannot share the same line as your normal telephone. It can only be used in isolation.

NOTE: Telephones with Mode 3 connectors should not be used with this equipment.

Contact Telecom if you are trying to use the modem on a small business key system such as a Commander, as these hand sets often signal to the PABX electronics with non standard tones and voltages. Damage to either the PABX or the modem could result from incorrect connection. A direct line from the local exchange may be needed in these situations.

Leased lines are special services providing a dedicated link between two sites. No switching is involved and hand sets are rarely provided. The DPX-213 can be configured to operate on two wire leased lines in synchronous or asynchronous modes. Special care has been taken with the design to ensure reliable operation in leased line mode, particularly with line changes caused by circuit re-routing. Section 5, Applications, details the recommended set-up strings for this use. Leased line also requires modifications to the line connector as shown in Appendix D.

3.5 Speed Matching

There are several forms of speed matching used in the DPX-213. The autobaud feature automatically senses the terminal speed from the typed AT commands and sets the modem interface speed to match the terminal. The autoranging feature automatically senses the line speed of the remote modem and adjusts to it in both originate and answer modes.

Additionally, there is a Constant Speed Interface (CSI) on the DPX-213 modem which allows your terminal to remain at the same speed, say 9,600 bps, for all 300, 1200 or 2400 bps full duplex calls. This simplifies operation with mini-computer systems provided you support flow control and avoids data loss if there is a speed mismatch in the system.

3.6 Flow Control

Flow control is needed whenever one device in the system runs faster or slower than another, or there are delays in transmission while errors are corrected. Flow control can be In-band using Xon and Xoff characters or Out-of-band using Request To Send (RTS) and Clear To Send (CTS). These are also referred to as software handshaking or hardware handshaking. It is legitimate to have different flow control techniques at each end of the link. The Xon and Xoff characters are user programmable in the DPX-213 and are stored in S-Registers 32 and 33 respectively.

Section 3

BEFORE YOU START

3-3

3.7 Escape Sequence

While off-line, the DPX-213 is in the Command State and all characters typed at your keyboard are scanned by the command interpreter awaiting AT commands. Once on-line, whatever is typed is sent to the remote modem. In order to get back in touch with the local command interpreter, perhaps to hang up or to change parameters, an escape sequence must be sent.

The industry standard "+++" escape sequence does not hang up the line or interfere with other settings and is entered by pausing for a few seconds, typing

+++

, and then

pausing again. Do not press

(Carriage Return or Enter). Typing the escape sequence returns you to the On-line Interactive State where the AT commands are active. For example, typing

athK

will hang up the call.

3.8 Advanced Features

The DPX-213 has MNP-4 error correction and MNP-5 data compression software. These are disabled in the factory defaults and must be specifically enabled if required. The Constant Speed Interface is active by default and allows terminal speeds from 300 to 9,600 bps to be automatically supported. The modem will normally attempt to establish all calls at 2,400 bps unless commanded otherwise or the remote modem cannot support this speed.

The modem automatically adjusts the transmit or receive speed to match the modem at the other end of the link. The line speed of the connection is displayed as the modem goes online.

The Constant Speed Interface facility, error correction and data compression are powerful features, but can result in problems if your terminal does not support flow control. If you are obtaining errors, or characters are garbled or missing whenever these features are invoked, it is likely there is a flow control problem. Check your communications software manual, the flow control sections (see Index) and the relevant AT commands of this manual.

To reduce the risk of unauthorised entry to your system, the DPX-213 features password verification. A password may be stored in the DPX-213 permanently and only those calls meeting the incoming password challenge are allowed access to the host.

The DPX-213 also contains an alarm feature that will dial a remote modem when an external device indicates that an event has occurred. The modem will connect with the remote modem and attempt to send a previously stored string.

BEFORE YOU START

Section 3

3-4

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Section 4

AT COMMAND SET

4-1

4.0 AT COMMAND SET

This Section contains some useful information about entering commands into the DPX213, the 'AT' command syntax and the different operating states. The Section also contains

a complete alphabetical listing of all commands.

4.1 Command Line and Command Entry

The DPX-213 uses the common AT command set which Dataplex has extended to cover additional features. The attention code, the letters 'AT', must precede all command lines to the DPX-213. This code may be in either upper or lower case. The modem uses the AT characters to detect the baud rate and character format of the incoming data. In this way, each command line can be at a different baud rate if desired. Once the AT sequence has been entered, the baud rate and character format are fixed for the remainder of that command line.

Typing AT while off-line will alert the internal control processor, but while on-line, the 'pause'

+++

'pause' escape sequence must be entered.

Some AT commands act on S-Registers. These are storage locations where various operating parameters are stored. These parameters control various modem features, such as the number of rings to count before answering an incoming call, the delay after dialling and before carrier detect, and so on. Refer to Section 8 for a full description of the SRegisters used in the DPX-213.

A command line to the DPX-213 consists of an attention code, one or more commands, and a carriage return (

). A command line may contain up to 129 characters

(including the attention code and the carriage return). Should you enter more than 129 characters, the DPX-213 will abort the command and return an ERROR code. Re-enter the command sequence in two smaller command lines.

Commands may be concatenated to save time. For example

at&fs0= 5d1234567K

causes the DPX-213 to recall

the factory configuration, set S0=5 (answer telephone on 5th ring) and then dial 1234567. Do not type AT more than once on any line or the AT character will be interpreted as command and not Attention.

For example you can enter commands separately:

1. Entering

atx3K

will cause the modem to blind dial (not wait for dial tone).

2. Entering

ats0=4K

will cause the modem to answer on the fourth ring.

AT COMMAND SET

Section 4

4-2

3. Entering

ats7=60K

will cause the modem to wait 60 seconds for

carrier from the answering modem.

4. Entering

atdn5K

will cause the modem to dial the number stored in

location 5.

Or type one concatenated string:

atx3 s0=4 s7=60 dn5 K

which has the same

effect (spaces between commands are ignored and are optional).

The above command descriptions have numeric modifiers to allow selection from one of several command options. These are usually shown as parameters 0 to 9. Where a numeric selection is omitted, the command processor assumes a zero (0) has been entered. For example AT*W is interpreted as AT*W0.

Commands take a variable time to execute, depending on the length of the command line and the type of command. The DPX-213 also takes a short period (750 microseconds) after the end of one command (the transmission of the result code) before it is ready to accept the next command. During this time the DPX-213 is resetting its internal registers in preparation for the next command. If communications equipment sends an 'AT' sequence during this 750 microsecond period, the 'AT' and subsequent command will be ignored.

4.2 Attention Code Syntax

It is possible to disable the AT command sequence by using the AT*D1 (Dumb Mode) command. In this mode, the unit will not respond to any AT sequence. The only way to reset the unit from this state is to carry out a power up reset (if not stored in NVRAM).

A description of the syntax for entry of AT commands follows:

Carriage Return

Command lines end with the carriage return character

. The value of this character is stored in Status register S3, and may be changed if desired. The default value of the carriage return is ASCII code 13 {0D HEX}.

Backspace

If an incorrect entry is made in a command line before

is depressed, the backspace key (E) can be used to erase the mistake. The backspace key will erase all characters up to, but not including the attention code (AT). The backspace character is stored in Status register S5. The default value is ASCII code 8.

Section 4

AT COMMAND SET

4-3

Repeat Command

When the DPX-213 is in Local Command State (waiting for an attention code), entering the characters

will cause the DPX-213 to repeat the last command line. The 'A'

character can be in either upper or lower case. If an

is entered directly after turning

on the power, the modem will return an ERROR code.

Command Parameters

Most commands to the DPX-213 have several parameters. These parameters select the various options for each command. Should the parameter be missing for a particular command, the modem will substitute the value 0. Should a parameter be outside the defined range, the modem will return an ERROR code.

Result Codes

After the DPX-213 has executed each command line, it returns a result code to show the status of the command. The result is in the form of digits (0 to 233) or text. Results displayed in digit format are often used when the modem is being controlled by a computer. Results displayed in the text format are suited to terminal control. Result codes can be disabled by setting Quiet Mode (ATQ1).

Status Registers

Configurations are stored in the Status Registers, called 'S-registers'. The DPX-213 has 24 Status Registers (of which, some are reserved for future expansion or used to maintain compatibility with the DPX-224). Most commands in the DPX-213 alter values in the status registers.

4.3 DPX-213 Operating States

There are four distinct operating states for the DPX-213:

1. Idle State

2. Command State

3. Data State

4. On-line command State

A description of each operating states follows.

AT COMMAND SET

Section 4

4-4

1. Idle State

This state is entered shortly after power is applied to the modem and the power-up self test has been passed. It can also be entered after the modem has executed a nondialling command line. In this state, the modem is waiting to autobaud an AT sequence from the DTE or awaiting a ringing signal from the telephone line. If a valid 'AT' entry is detected, the modem enters the Command State.

If a valid ringing signal is detected the modem will send a RING message to the DTE at the last autobaud speed. If set to answer (S-Register 0 not set to 0) the modem will go off-hook and enter the Data State after a predetermined number of rings (S0).

2. Command State

During the Command State, the modem buffers command characters from the DTE until a carriage return (

) character is received. The modem will buffer up to 48 characters not including the initial 'AT' characters. If more than 48 characters are received the modem will insert a carriage return character and return an ERROR message signifying buffer overflow. If no overflow is detected and a carriage return character is received the modem will start to sequentially execute commands in the buffer until one of the following:

1. Carriage Return Detected

If this is part of a dial command, the DPX-213 will execute the following sequence: go off-hook, look for dial tone (unless set to blind dial) and then proceed to place the call.

2. Illegal Command Encountered

The modem will execute the following sequence: send an ERROR message to DTE, empty the command buffer and return to idle state.

3. Answer (ATA) or On-line (ATO) Command Received

The modem will enter the Data State.

Section 4

AT COMMAND SET

4-5

3. Data State

After an ATA (Answer) or ATO (Originate) command, the modem enters the Data State. The modem will attempt to handshake with the remote modem or if already connected will enter begin to exchange data.

The normal Data State is transparent and all characters issued by the DTE are passed to the remote end. Sometimes you may need to abort the operation and regain control of the local modem instead of the remote DTE. This is possible in the On-line Command State and is selected with the escape sequence.

Several other interface or line events that will cause the modem to drop out of transparent data transmission (Data State) to local control (On-line Command State) are described as follows:

1. Escape Sequence Detected ('pause'

+++

'pause') The modem will leave the data state and execute the following sequence: send an "OK" message to the DTE, clamp transmit data to mark, disable receive data to DTE and enter the On-line Command State.

2. Loss of Carrier Detected (provided S10 is not set to 255)

The modem will execute the following sequence: send a "NO CARRIER" message to the DTE, go on-hook and returns to Idle State.

3. DTR Dropped (provided DTR is not forced on and AT&Dn is set)

The modem will execute the following sequence: send a "NO CARRIER" message to the DTE, go on-hook and return to Idle State.

4. DTR Dropped (provided DTR is not forced on and AT&D2 or AT&D3 is set)

The modem will execute the following sequence: send a 'NO CARRIER' message to the DTE, go on-hook and return to Idle State.

AT COMMAND SET

Section 4

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4. On-line Command State

This state is entered after a 'pause'

+++

'pause' escape sequence has been

detected. The modem link is preserved and the user communicates with the local modem and not the remote DPX-213. All data sent by the remote modem is ignored but carrier is still monitored and the message "NO CARRIER" will be issued if loss of carrier is detected. Additionally, some RTS, DTR, or make busy control changes are acted upon. Any normal command that can be issued in command state can now be issued in the On-line Command State while a call is active. However, some commands have no meaning such as ATA, and will return ERROR. The most common use of the On-line Command State is to issue the ATH command to hang up the call. Other options to exit the On-line Command State are:

1. ATH Command Received

The modem will execute the following sequence: send an "OK" message to the DTE, go on-hook (hang-up) and return to Idle State.

2. ATZ Command Received

The modem will execute the following sequence: reset the configuration to the customer stored value, go on-hook (hang-up), send an "OK" message to the DTE and return to Idle State.

3. ATO Command Received

The modem will execute the following sequence: send a "CONNECT" message, unclamp received and transmitted data, and returns to the Data State.

4.4 AT Command Set

The remainder of this Section contains an alphabetical listing of all commands, including full syntax and details of use. For each command, parameters, default settings (or AT&F) and the Status Register (S-register) bits that store the present command setting are provided. If the value in a status register effects the operation of a command, the register with its default value is shown. For example: S7 (45 seconds).

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Dataplex DPX-213 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual