mpiControlObjectPtr
Declaration
mpiControlObjectPtr(MPIControl control, MPIControlObjectType objectType, int32_t objectIndex, MPI_BOOL host, MFWObjectPtr *objectPtr);
Required Header: stdmpi.h
Change History: Added in 04.00.
Description
mpiControlObjectPtr gets a pointer to an object, specified by the objectType and objectIndex. The objectPtr can be a host address or a controller address, depending on the host flag. If the objectIndex is 0, mpiControlObjectPtr sets the objectPtr to the base of the object array, even if the number of objects in the array is zero.
WARNING! Bypassing the MPI to access the controller’s memory directly is not guaranteed to be binary compatible with future MPI libraries. The controller’s memory map is firmware version dependent. If your application directly accesses the controller’s memory, you must re-compile your application when upgrading to newer MPI versions.
| control | A handle to a control object. |
|---|---|
| objectType | The type of object; |
| objectIndex | An index into an array of objects. |
| host | TRUE or FALSE. When TRUE, objectPtr is a host address based pointer. When FALSE, objectPtr is a controller address based pointer. |
| *objectPtr | A pointer to an object address |
| Return Values |
|---|
| MPIMessageOK |
| MPIControlMessageOBJECT_INVALID |
| MPIControlMessageOBJECT_INDEX_INVALID |
Sample Code
Configure a set of addresses to contain pointers to axis memory on the controller. This would be useful for configuring the data recorder.
MFWAxisData *axisDataPtr; void *addr[2];
returnValue = mpiControlObjectPtr(control, MPIControlObjectTypeAXIS_DATA, 0, TRUE, /* host address */ &axisDataPtr);
if (returnValue == MPIMessageOK) { addr[0] = &axisDataPtr->Status; addr[1] = &axisDataPtr->TC.Velocity; }