ASYNC GETBAUDRATE: Difference between revisions
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This function returns the bit rate. | This function returns the bit rate. | ||
; Category: IOCTL_ASYNC (01h) | ;Category: IOCTL_ASYNC (01h) | ||
; Function: ASYNC_GETBAUDRATE (61h) | ;Function: ASYNC_GETBAUDRATE (61h) | ||
==Parameter Packet Format== | ==Parameter Packet Format== | ||
None. Packet pointer must be NULL. | None. Packet pointer must be NULL. | ||
==Data Packet Format== | ==Data Packet Format== | ||
{|class="wikitable" | |||
!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. | |||
;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== | ==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. | 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== | ==Remarks== | ||
If a general failure error is not returned, the physical device driver returns the current bit rate of the COM device. | 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. | ;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. | ||
[[Category:IOCtl Commands]] | [[Category:IOCtl Commands]] | ||
{{DISPLAYTITLE:ASYNC_GETBAUDRATE (61h) }} | {{DISPLAYTITLE:ASYNC_GETBAUDRATE (61h)}} | ||
Revision as of 21:20, 3 May 2020
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.