ASYNC STARTTRANSMIT

This function behaves as if an XON was received (starts transmitting).

Category

IOCTL_ASYNC (01h)

Function

ASYNC_STARTTRANSMIT (48h)

Parameter Packet Format

None. Packet pointer must be NULL.

Data Packet Format

None. Packet pointer must be NULL.

Returns

If the call is made with invalid Parameter Packet or Data Packet pointers, a general failure error is reported, and this request is not performed by the physical device driver.

Remarks

If a general failure error is not returned by the physical device driver, this function allows data transmission to be resumed by the device driver if the data transmission was stopped because of a ASYNC_STOPTRANSMIT request, or because an XOFF character was received while the physical device driver was in Automatic Transmit Flow Control mode.

See ASYNC_GETCOMMSTATUS for other reasons why transmission might be disabled.