The IOCTL_PMI_GET_CAPABILITIES request obtains the capability and asset information about a power meter.

Major Code


Input Buffer

The AssociatedIrp.SystemBuffer member of the I/O request packet (IRP) points to an initiator-allocated buffer that is used both as the input buffer and the output buffer for the request. On input, this buffer contains a PMI_CAPABILITIES structure in which the Version and CapabilityType members are set to valid values. The CapabilitiesType member contains a PMI_CAPABILITIES_TYPE enumeration value that specifies the type of PMI capability information to be retrieved from the power meter. This value also determines the size of the output buffer required to contain this information.

Input Buffer Length

The Parameters.DeviceIoControl.InputBufferLength member of the IRP's current I/O stack location (IO_STACK_LOCATION) is set to the size in bytes of the buffer that is pointed to by the AssociatedIrp.SystemBuffer member. This size must be greater than or equal to sizeof(PMI_CAPABILITIES) or the request will fail with an error status of STATUS_INVALID_PARAMETER.

Output Buffer

If the request completes successfully, the buffer pointed to by the AssociatedIrp.SystemBuffer member contains the requested PMI capability information. Located at the start of this buffer is a PMI_CAPABILITIES structure that indicates the type and size of the information in the buffer.

Output Buffer Length

The Parameters.DeviceIoControl.OutputBufferLength member of the IRP's current I/O stack location is set to the size in bytes of the buffer that is pointed to by the AssociatedIrp.SystemBuffer member. For the request to succeed, this size must be large enough to contain the PMI capability information specified by the PMI_CAPABILITIES_TYPE input parameter value. Otherwise, the request will fail with error status STATUS_BUFFER_TOO_SMALL.

Status Block

The Information member is set to the size, in bytes, of a PMI_CAPABILITIES structure and its variable-length data.

The Status member is set to one of the following values:


The IOCTL_PMI_GET_CAPABILITIES request queries the PMI capabilities or asset information of the power meter. The input PMI_CAPABILITIES enumeration value specifies the type of capability information to be returned. The data type and contents of the output buffer vary based on the data requested.

The following table describes the type of data that is returned for the specified PMI_CAPABILITIES_TYPE enumeration value.

PmiMeteredHardware A PMI_METERED_HARDWARE_INFORMATION structure that specifies the hardware devices that the power meter monitors.
PmiReportedCapabilities A PMI_REPORTED_CAPABILITIES structure that specifies the types of PMI capabilities the power meter supports.
Note The PMI_REPORTED_CAPABILITIES structure is variable-length. The driver must fail this IOCTL request if the output buffer (referenced by the MdlAddress member of the IRP) is too small.


Windows version Available in Windows 7, Windows Server 2008 R2, and later versions of the Windows operating systems.
Header pmi.h (include Pmi.h)

See Also