Contents:

Product Features

Installing Your Modem

Using the AT Command Set

Upgrading your Modem

Modes of Operation

Dialing, Answering, and Hanging Up

Configuring with DIP Switches

Working with Memory

Controlling Result Code Displays

Controlling EIA-232 Signaling

Accessing and Configuring the Courier 56K Business Modem Remotely

Controlling Data Rates

Dial Security

Flow Control

Handshaking, Error Control, Data Compression, and Throughput

Displaying Querying and Help Screens

Testing the Connection

Dedicated/Lease Line and Synchronous Applications

Troubleshooting

Appendixes

S-Registers

Alphabetic Command Summary

Flow Control Template

Result Code Meanings and Sets

Technical Information

V.25 bis Reference

ASCII Chart

Fax Information for Programmers

Viewing LEDs

Regulatory Information and Limited Warranty

Glossary

Courier 56K Business Modem Command Reference

Accessing and Configuring the Courier 56K Business Modem remotely

This chapter contains information about:

• Setting Up Remote Access
• Accessing The Host
• Quitting a Remote Access Session

Overview

You can set up the Courier 56K Business Modem so other devices can view or change its configuration remotely.

You should be familiar with these terms before you continue:

Setting Up Remote Access

At the Host Courier 56K Business Modem

1. Prepare to send AT commands by putting your communications software in Terminal Mode.
2. Enable remote access.
   
   Set Register S41 for a value of 1 or greater. S41 sets the number of login attempts available to the remote user. A setting of zero allows no login attempts disabling remote access.
   
   Example: Sending ATS41=1&W allows for 1 login attempt by a remote user.
   
   Note: This method will not work if the Courier 56K Business Modem is attached to certain synchronous devices. Refer to the Dedicated/Lease Line and Synchronous Applications chapter in this guide.
   
   
3. Set one or two remote-access passwords.
   
   You can set two passwords to allow different levels of access to each Courier 56K Business Modem.

Example: Sending AT%P1= wombat will allow a remote user to log in with the password "wombat." The user can view and change the Courier 56K Business Modem’s configuration.

Note: Remote-access passwords can be up to eight alphanumeric characters long, and are not case-sensitive.

Other Remote-Access Commands

The table below is a list of remote-access configuration commands.

Example: Sending AT%P1= will erase the view and change password.

WARNING: If you erase the %P1 password without disabling remote access (using ATS41=0), anyone could access the Courier 56K Business Modem and change its configuration.

Accessing The Host

At the Guest Device

The guest device requires no configuration to access the host. Follow these steps:

1. Be sure that the host device has enabled remote access and is set to auto-answer (ATS0=1). Know the password, if you will need one.
2. Call the host device (although it doesn’t matter which device originates the call).
3. After a connection is established, do this:
   
   Pause 4 seconds.
   Type 4 tildes: ~~~~
   Pause 4 seconds.
   
   Note: The administrator of the host device can change the remote-access character using S-Register 42, and the pause duration using S-Register 43. Refer to the S-Registers chapter of the Appendixes section for more information.
   
   
4. You should see a display similar to this:
   
   U.S. Robotics Courier 56K Business Remote Access Session
   Serial Number 000000A000000001

   Password (Ctrl-C to cancel)?
   
   There is a three minute time limit for entering the password. If the number of unsuccessful login attempts exceeds the set limit, the host device returns online and refuses any further login attempts during the remainder of the connection.
   
   When the host accepts the password, the following message and prompt will appear on your screen:
   
   Remote Access granted
   
   Remote->
   
   Note: You may not be prompted for a password. If you aren’t, password security is not active. The following prompt appears on your screen after you type the four tildes:
   
   Remote Access granted (query only)
   
   Remote->
   
   Note: During a remote-access session, the maximum number of characters between carriage returns is 40.

Viewing and Changing the Host’s Configuration

Once you've gained guest access to a host, you can communicate with the host just as if you were entering commands from its attached computer.

Depending on your access privileges, you can use the regular set of Courier 56K Business Modem AT commands.

CAUTION: Be careful not to send ATZ or ATZ! or you will lose the connection!

Remote Configuration Commands

There are special commands that can be used only during a remote-access session.

You can change the host Courier 56K Business Modem’s serial port rate by using the AT%Bn command.

Example: Sending AT%B6 will change the Courier 56K Business Modem’s serial port rate to 9600 bps.

You can use the AT%Fn command to control the data format.

You can use the AT%Cn command to control whether and when to apply changes to the configuration.

Example: Sending AT%C1 will cancel any changes made to the modem during a remote access session and restore it to the original configuration.

Note: Even though, by default (%C0), the changes you make do not take effect until the next connection, the new configuration is reflected immediately in inquiry responses (ATIn). Commands that have been written to NVRAM (using &W) and forced configuration changes (%C2) will not be restored to their previous settings when you send the host AT%C1.

After you make changes to the host’s configuration, the remote- access prompt changes from Remote-> to Remote+>.

If you restore the original configuration using the AT%C1 command, the first prompt is restored, assuring you the original configuration is intact.

Quitting A Remote Access Session

If you want to quit the remote access login before you have entered the password, return online by pressing <Ctrl>C or typing ATO.

After you’ve entered the password, you can quit by sending one of these commands:

Note: Before you disconnect, issue the ATI5 command to the remote modem and check its S41 setting. Make sure S41 is set for a value of 1 or greater. If S41 is set to 0, when you disconnect you will not be able to access the remote modem again. To prevent this send ATS41=1&W before you disconnect.