ASYNC GETBAUDRATE

This function returns the bit rate.

Category: IOCTL_ASYNC (01h)
Function: ASYNC_GETBAUDRATE (61h)

Parameter Packet Format

None. Packet pointer must be NULL.

Data Packet Format

┌────────────────────────────────────┐
│Field        Length     C Datatype  │
├────────────────────────────────────┤
│Bit Rate     WORD       USHORT      │
└────────────────────────────────────┘

Bit Rate: A binary integer representing the actual bit rate of the COM device in bits-per-second, rounded to the nearest whole number.

Returns

If the call is made with an invalid Parameter Packet value, a general failure error is reported and valid information is not returned in the Data Packet.

Remarks

If a general failure error is not returned, the physical device driver returns the current bit rate of the COM device.

Note: If this function is called when the current bit rate setting of a COM port is greater than what can be stored in a 1-WORD field, the device driver sets the bit rate to 1200 bps (default value) and returns 1200 bps to the user.