Modem Troubleshooting
If after following the instruction provided on the Modem Setup page you are still unable to properly connect, see if any of the following symptoms applies to the problem:
Connects but displays "garbage" characters
"Error: Communications port is in use.." displays
"Unable to establish an asynchronous connection.." displays
Characters are echoed twice to the screen
Protocol cannot be changed from "telnet"
Modem dials and connects but immediately returns "No carrier" or "Framing or parity error"
Session hangs when entering block mode
Troubleshooting with Hyperterminal
If the session dials and connects but gibberish displays, the character composition is probably incorrect. The bits per character, parity and number of stop bit parameters must be identical at the calling and receiving modems. Verify that the character composition (i.e., 7e1 or 8n1) is correct in session settings.
Another application or session is currently using that COM port. Identify which application or session is using the port and disconnect or terminate it.
In versions 7.0A, B and D, if the I/O method in New Session Defaults is set for "Async" or "TAPI", the protocol in new sessions will be "telnet". This option will be disabled disallowing any changes. The correct protocol value for Async or TAPI I/O is "<None">.
To correct this issue, edit the New Session Defaults (Edit/Application Settings../New Session Defaults) to set TCP/IP as the default I/O method. For new sessions, you will then be able to set the I/O method to "Async" or "TAPI" and the protocol will automatically be set to <None>. To correct existing session files:
- Open the file
- Select Session/Disconnect to terminate any dial attempt
- Select Session/Session Settings..
- Click on the I/O category
- Set the I/O method to TCP/IP
- Reset the I/O method to Async or TAPI
- The protocol should automatically be set to <None>
- Save the session
Verify:
- The COM port settings are correct.
- The target is set to Modem (Session/Session Settings../IO/Advanced)
- The dial number is defined (Session/Session Set tings.../IO/Advanced)
- The modem is properly installed
This problem has been resolved for many 56 kB modems by disabling error control. The code to disable error control may be added to the modem initialization string (e.g., AT&C1&D2&M0). If your modem is not listed below, please refer to the modem's documentation for the correct code.
MODEM Code to disable error control
Diamond Supra 56 Express: \N0
US Robotics Sportster: &M0
Hayes: &Q0
Practical Peripherals &K3&M0
Session Hangs when Entering Block Mode
The modem may be set for XON/XOFF flow control. For US Robotics (3Com) modems, a hardware flow control template can be applied by setting the initialization string to AT&F1. To set hardware flow control and to disable error checking, the initialization string should be: AT&F1&M0. For other Hayes compatible modems, hardware flow control can be set by setting the initialization string to AT&H1&R2. To determine the correct command to set hardware flow control for other modem types, refer to the documentation included with the modem.
Troubleshooting with Hyperterminal
Hyperterminal is a simple modem connectivity tool included with all current versions of Windows and NT that supports TAPI or direct COM port connections. Using this tool, you can test the operation of your PC, local modem and remote modem without involving OutsideView.
To verify communication with the local modem:
- Start Hyperterminal (Start/Programs/Accessories/Hyperterminal/Hyperterminal)
- Name the session "Direct" and click "Ok"
- Set the "Connect Using" list to the COM port to which your modem is connected. If you are unsure of which COM port to select, open Control Panel, click on "Modems" and see which one is used.
- The COM port properties may be left at their default values.
- Save this session (File/Save)
- In the terminal window, type AT then press the Enter key.
- You should see "AT" followed by "OK" on the next line.
- If nothing appears in the terminal window, type ATE1 and press the Enter key.
- Type AT and press Enter once again.
- If there is still no response, try turning the modem off then back on (assuming an external modem) and try AT and then Enter once again. If your modem is internal, you will need to restart your PC and restart Hyperterminal for this test. If you cannot obtain an echo of the AT characters sent and an "OK" response, your modem or other hardware may be defective.
After verifying communication with the local modem, test the remote modem connection.
- Enter ATDT<dial number> and press Enter. Dial number is the number of the remote modem. For example, to dial a remote modem at 800-555-1234, the command is:
- ATDT800-555-1234
- followed by pressing Enter.
The modem should dial and connect. (You will not be able to access any host application that displays in block mode using this technique.)