Setting up the 3ComImpact™ IQ for 230.4 Kbps Mode

Setting up the 3ComImpact™ IQ for 230.4 Kbps Mode

Last Revision: 07/9/98

Model Number: 3C882

The 3ComImpact IQ ISDN modem allows for transfer rates of up to 230.4 Kbps (before compression). However, most PCs require the purchase of additional hardware, such as a COM Port card, to take advantage of this speed increase and eliminate the bottleneck of standard serial ports. If your PC’s COM port can handle speeds of up to 230.4 Kbps, follow these instructions.

Before You Begin

You will need the 3ComImpact™ IQ Windows Installation diskette provided in your 3ComImpact IQ ISDN modem package. In addition, you will need a COM port driver card that supports speeds up to 230.4 Kbps (16650 UART or higher). 3Com has tested various cards; these are listed at the end of this document. Please make sure that you are able to communicate to the 3ComImpact IQ in Autobaud mode through this COM port card before changing the modem’s operations to 230.4 Kbps.

If you’re running Windows 95 or Windows NT 4.0, you will also need to install the 230.4 Kbps driver that was provided to you in the impact.inf file. Please follow the instructions for the appropriate operating system that are available on the 3Com web page. Your 3ComImpact IQ User Guide also contains instructions for installing this .inf file.

Setting up the 3ComImpact™ IQ for 230.4 Kbps mode

Windows 95 and Windows NT 4.0 contain a terminal emulation program called 'HyperTerminal' which can be found by clicking on Start, Programs, then Accessories (any other terminal emulation program will work as well). You will need to create a new session to communicate directly to the 3ComImpact™ IQ to manually set the modem to work at 230.4 Kbps. Follow these steps to create a new connection:

1. Double click on the Hypertrm icon.

2. Give the session a name (i.e.: '3Com IQ - 115.2K').

3. Select an icon or press OK.

4. Another window will appear titled 'Phone Number'. Since you want to communicate directly with the modem, you do not have to enter a phone number. To bypass entering a phone number, click on the right arrow under ‘Connect Using’ and select the Com port to which the 3ComImpact™ IQ is connected. (i.e.: 'Direct to Com 3'). Click OK.

5. In the next window entitled 'Com X Properties', change the Bits Per Second to 115200. Click OK.

You should now see a blank screen with a blinking cursor in the upper left hand corner. The PWR and DTR LED’s on the modem should both be on.

6. Type AT and press return.

The 3ComImpact™ IQ should respond with an "OK". Repeat typing AT and press return if you do not receive an "OK" message from the modem. If this method should all fail, repeat steps 1-5 above.

After receiving an OK response, type AT\S and press return. The second line of information that will appear will reflect the Serial BPS and will most likely show 115200 in the column to the right. In the 3rd column to the right, it will most likely say 'AT$B0 (AUTOBAUD)'. When in 'Autobaud' mode, the modem will communicate at a maximum speed of 115,200 bps. The following steps will change the serial speed rate to a fixed 230.4 Kbps.

1. Type AT$B230400 and press return. Your PC may appear to be frozen or you may see meaningless characters on your screen. This is normal and does not indicate a problem.

2. Click FILE, followed by PROPERTIES, and then click the CONFIGURE button. This opens the Com Port Properties window.

3. Change Bits Per Second to 230,400 bps.

4. Click OK. Then drop the 115,200 bps connection by clicking DISCONNECT in the main screen.

5. Reconnect to the modem by clicking CONNECT. Type AT and press return. You should receive an OK response. Next, type AT\S to confirm that the modem is set to 230,400 bps for the Serial BPS. Save the modem’s new settings by typeing AT&W and press return.

6. Exit HyperTerminal.

Note: User’s of Pacific Commware’s TurboExpress Port 920 card do not have to go through the above mentioned steps. Simply run the program provided by Pacific Commware to force the modem into 230.4 Kbps mode.

If you are using Windows 95 or Windows NT 4.0, you will have to reinstall the 3ComImpact IQ driver. Now you are ready to place calls at serial speeds of up to 230.4 Kbps.

Troubleshooting: Restoring the 3ComImpact IQ to Autobaud

This section offers instructions should you experience any of the following concerns:

• You can not communicate with the unit even though the DTR and Power LEDs are lit green.

• You need to use the 3ComImpact IQ configuration utility which requires the modem to operate at ‘Autobaud’.

• The D, B1 and B2 LEDs all light up in green when power is first applied. This is an indication that the unit is set to a fixed baud rate. Follow this special procedure to regain communication control between the PC and the modem.

1. Open HyperTerminal according to the directions above. Click FILE, followed by PROPERTIES, then CONFIGURE. This will open the Com Port Properties.

2. Change the Bits Per Second to a low baud rate (such as 2400). Click OK.

3. Power up your 3ComImpact IQ and then immediately type the letter "a" repeatedly, from your keyboard, until you see the letter "a" appear on the screen. (This may take approximately 10 to 15 seconds.) When you see the letter "a", this indicates that the ISDN modem is now running in Autobaud mode, and will adapt itself to the baud rate of your computer’s COM port (note, this has to be a baud rate of 115200 bps or less).

4. Send the command AT&W to the 3ComImpact IQ to save this change.

Notes:

Unless you saved the modem’s new configuration with the AT&W command, the 3ComImpact IQ will automatically be reset to Autobaud whenever the hardware is power cycled. Should your ISDN modem reset to autobaud (verify using the command AT\S), you will have to repeat the steps outlined under "Setting up the 3ComImpact IQ for 230.4 Kbps mode."

Interoperability Testing:

3Com has tested all of the cards listed below with Windows 95. Windows NT 4.0 has been tested only with Lave Computer’s Lava Link card; however, several of our customers have been successful with Digi International’s Digi AccelePort C2 card under Windows NT 4.0.

For sales and technical support information on accelerator cards, please contact the corresponding manufacturers.

Pacific CommWare, Inc.

tel: (800) 960-6444

fax: (541)482-2627

pcwinfo@turbocom.com

www.turbocom.com

(TurboExpress Port 920 card / 16750 UART : Supports Windows 3.1x, Windows 95 and Windows NT)

Lava Computer MFG Inc.

tel: (416)674-5942

fax: (416)674-8262

tech@lavalink.com

www.lavalink.com

(Lava Link-650 card / 16650 UART : Supports Windows 3.11 and Windows 95; drivers for Windows NT is currently in beta.)

Digi International Inc

tel: (800)344-4273 (612)943-9020

fax: (612)943-5398

info@digibd.com

www.digibd.com

(Digi AccelePort C2 card / 16650 UART : Supports Windows 3.1x, Windows 95 and Windows NT.)

Hayes Microcomputer Products, Inc.

tel: (404)441-1617

fax: (404)449-0087

support@os.hayes.com

www.hayes.com

(Hayes ESP card / (16650 UART??) : Supports Windows 3.x, Windows 95 driver available on Hayes’ website.)