IOCTL_PAR_GET_DEFAULT_MODES IOCTL

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

IRP_MJ_DEVICE_CONTROL

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:

Requirements

   
Header ntddpar.h (include Ntddpar.h)

See Also

PARCLASS_NEGOTIATION_MASK

IOCTL_PAR_GET_DEVICE_CAPS

IOCTL_IEEE1284_GET_MODE

IOCTL_IEEE1284_NEGOTIATE