PRWIN9204001: Data Errors on 14400 Baud Serial Communications

ID Number: Q83232

3.10

WINDOWS

buglist3.10

Summary:

PROBLEM ID: WIN9204001

SYMPTOMS

When an application uses the CBR_14400 constant to specify 14,400

baud serial communications, frame errors or other communication

problems result once data transmission begins.

CAUSE

In the Windows COMM.DRV driver, a table entry that corresponds to

CBR_14400 contains an incorrect value.

RESOLUTION

Set the BaudRate field of a DCB (device control block) structure to

14400 (the desired baud rate) not to the CBR_14400 constant.

Microsoft has confirmed this to be a problem in Windows version

3.1. We are researching this problem and will post new information

here as it becomes available.

More Information:

An application specifies one of the CBR_* constants as the BaudRate

field of a DCB structure. The application calls the SetCommState

function with a pointer to the DCB structure to modify the state of a

communication device.

The CBR_* constants were added to Windows at version 3.1. Directly

specifying the desired baud rate continues to be supported.

Additional reference words: 3.10