ASYNC SETBREAKON: Difference between revisions
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If a general failure error is not returned, the physical device driver generates the break signal immediately. It is not considered an error if the physical device driver is already generating a break signal. The device driver does not wait for the transmit hardware to become empty. Note that more data is not given to the transmit hardware until the break is turned off. The break signal is always transmitted, regardless of whether or not the physical device driver is transmitting characters for other reasons. | If a general failure error is not returned, the physical device driver generates the break signal immediately. It is not considered an error if the physical device driver is already generating a break signal. The device driver does not wait for the transmit hardware to become empty. Note that more data is not given to the transmit hardware until the break is turned off. The break signal is always transmitted, regardless of whether or not the physical device driver is transmitting characters for other reasons. | ||
[[Category:IOCtl | [[Category:IOCtl Function]] | ||
Latest revision as of 18:56, 22 October 2021
This function sets break on.
- Category
- IOCTL_ASYNC (01h)
- Function
- ASYNC_SETBREAKON (4Bh)
Parameter Packet Format
None. Packet pointer must be NULL.
Data Packet Format
| Field | Length | C Datatype |
|---|---|---|
| COM Error Word (COMERR) | WORD | USHORT |
- COM Error Word (COMERR)
- The physical device driver returns this information if a general failure error is not reported. See ASYNC_GETCOMMERROR for COMERR definition. The COM device error information is not cleared by this action.
If, after processing this Close request, the port will not be open (from another Open without a Close), a CLOSE request packet causes break to be turned off.
Returns
If the call is made with an invalid Parameter Packet pointer and a general failure error is reported, this function is not performed and valid information is not returned in the Data Packet.
Remarks
If a general failure error is not returned, the physical device driver generates the break signal immediately. It is not considered an error if the physical device driver is already generating a break signal. The device driver does not wait for the transmit hardware to become empty. Note that more data is not given to the transmit hardware until the break is turned off. The break signal is always transmitted, regardless of whether or not the physical device driver is transmitting characters for other reasons.