IOCTL_PAR_GET_DEFAULT_MODES IOCTL (ntddpar.h)
The IOCTL_PAR_GET_DEFAULT_MODES request returns the default write (forward) and read (reverse) IEEE 1284 protocols that the system-supplied bus driver for parallel ports uses. The default write protocol is CENTRONICS; the default read protocol is NIBBLE.
For more information, see Setting and Clearing a Communication Mode for a Parallel Device.
Major code
Input buffer
None.
Input buffer length
None.
Output buffer
The AssociatedIrp.SystemBuffer member points to a PARCLASS_NEGOTIATION_MASK structure that the client allocates to output mode information. The system-supplied bus driver for parallel ports sets the usReadMask member and the usWriteMask member. The default write mode is CENTRONICS; the default read mode is NIBBLE.
Output buffer length
The value of the Parameters.DeviceIoControl.OutputBufferLength member is set to the size, in bytes, of a PARCLASS_NEGOTIATION_MASK structure.
Status block
If the request is successful, the Information member is set to the size, in bytes, of a PARCLASS_NEGOTIATION_MASK structure. Otherwise, Information is set to zero.
The Status member is set to one of the generic status values returned by device control requests for parallel devices or to the following value:
STATUS_BUFFER_TOO_SMALL
The value of the Parameters.DeviceIoControl.OutputBufferLength is less than the size, in bytes, of a PARCLASS_NEGOTIATION_MASK structure.
Requirements
| Requirement | Value |
|---|---|
| Header | ntddpar.h (include Ntddpar.h) |