Error Messages or Hangs Using 3Com EtherLink III (3C509) (103733)

SYMPTOMS

You may receive error messages or your computer may stop responding (hang) when you use a 3Com EtherLink III (3C509 or 3C509TP) network adapter card if your card is configured for a maximum modem speed setting that is too high. If a problem occurs when you start (boot) your computer, an error message such as the following may occur:

Error #5740 the Protocol Manager Reported a Protocol Failure at Initialization

RESOLUTION

To correct these problems, run the Menu program on the 3C509 Utility disk supplied with your EtherLink card. The following instructions describe how to use the Menu program to change the maximum modem speed for your EtherLink card:

Start the Menu program.
From the main menu, choose Diagnostic and Configuration Program.
On the next menu, choose the Install option.
Choose Configure Adapter to open the Adapter Configuration menu.
From the Adapter Configuration menu, select the Maximum Modem Speed option.
The default speed, 9600, is usually appropriate. If your machine is slower, select a lower value.

MORE INFORMATION

The following quote, from page 2-4 of the "EtherLink III Adapter Guide," describes the function of the Maximum Modem Speed option:

Selecting a modem speed tells the adapter how long it can disable interrupts without causing problems with the serial port. The lower the modem speed, the longer the adapter can keep interrupts disabled. On slower computers, running with longer disabled interrupts can improve network performance. On those computers, changing the option setting to 2400, 1200 or No Modem may improve performance. On faster computers, there is little performance difference between the settings.

If you experience problems with your modem, such as dropped characters or excessive retries, selecting a higher option setting should help. If the problem is not due to the EtherLink III driver, changing the option setting does not make a difference.

If you experience compatibility problems between your adapter and another device in the system other than a modem, selecting a higher option may help.

NOTE: The default value (9600 bits per second [BPS]) works whether you have a modem or not, or even if the modem is slower than the default (example, 2400 BPS). Do not change the default option setting unless you experience problems.