IOCTL_SERIAL_CLR_DTR IOCTL (ntddser.h)
The IOCTL_SERIAL_CLR_DTR request clears the data terminal ready (DTR) control signal.
To set DTR, a client can use an IOCTL_SERIAL_SET_DTR request.
If the handshake flow control of the device is configured to automatically use DTR, a client cannot clear or set DTR.
Major code
Input buffer
None.
Input buffer length
None.
Output buffer
None.
Output buffer length
None.
Status block
The Information member is set to zero.
The Status member is set to one of the Generic Status Values for Serial Device Control Requests. A status of STATUS_INVALID_PARAMETER indicates that the handshake flow control of the device is set to automatically use DTR.
Requirements
| Requirement | Value |
|---|---|
| Header | ntddser.h (include Ntddser.h) |