LabVIEW call Win32 API DLL function from third party

Question

Hi everyone,
I'm trying to build a LabVIEW 2010 interface on 32-bit Window XP system to configurate and communicate to an Anglient laser head through its USB expansion box. I contacted the vendor and they shared a win32 API with some dll files. I started with a function called "A55292Find", but the CLF node always pop up error 1097.I checked the MSDN to get the corresponding LabVIEW data type for CLF.
My question is: Do I need to initialize those arguments? (How can I know the values of them if initialization is needed?)
Could anyone help me figure out what's the problem?
Here is what I have from API documents about this function:
The A55292Find function returns lists of handles and board types for all the 55292 USB
Expansion Modules connected to the system.
A55292RC __cdecl A55292Find(
HANDLE hBoxes[], // List of handles for the boxes found. (as Unsigned 32-bit integer numeric)
BOARDTYPE PortABrdType[], // List of board types for slot A boards (as Unsigned 16-bit integer numeric)
BOARDTYPE PortBBrdType[], // List of board types for slot B boards (as Unsigned 16-bit integer numeric)
WORD *spMaxBoxes); // dimension for all of the passed arrays. (as Unsigned 16-bit integer array data pointer)
// (function return type as Unsigned 32-bit integer numeric)
Parameters
HBoxes[] Array that will receive the list of HANDLES for all the 55292 boxes connected.
PortABrdType[] An array that will receive Slot ‘A’ board type information for each 55292 box.
PortBBrdType[] An array that will receive Slot ‘B’ board type information for each 55292 box.
spMxBoxes Passes the maximum number of values that can be held in hBoxes, PortABrdType, and PortBBoardType arrays to the A55292Find routine and returns the actual number of boxes found
The return value will be one of the following A55292RC return codes:
Value Meaning
A55292_NO_ERROR No error
A55292_TIMEOUT Timeout accessing a shared memory
Remarks
This routine must be called to obtain handles and board type information used in calling all the other routines. If there are significantly more array elements than boxes, the routine will take longer to complete.
These are the definitions: 
typedef DWORD A55292RC; enum{A55292_NO_ERROR, A55292_HANDLE_ERROR,...}
typeder WORD BOARDTYPE; enum{A55292_PCAL_BOARD, A55292_NO_BOARD, ...}
Thanks a lot,
Kang
Solved!
Go to Solution.
Attachments:
call A55292Find.vi ‏10 KB

Answer 1

nkang11 wrote:
Hi Mr. Kalbermatter,
As you told me, I should try to use the defined enumeration words as control and indicator.
For the previous CLF node, it successfully returned the hardware configuration (I have only connected a board at slot A):
But I really want to see a string return as "A55292_PCAL_BOARD" which is defined by "typedef WORD BOARDTYPE; enumeration {...}; Does that mean I need to change the data type or do something like "converter"? Or initialize the array first, then convert it to string type?
Right now, I'm trying to open the laser card by using "A55292PcalOpen(HANDLE hDev, SLOTSELECT SlotSelector);" function which requires to use the enumeration constants from " typedef WORD SLOTSELECT; enum {A55292_PORT_A, A55292_PORT_B};" but I'm confused to shot an constant control to a new CLF node.
Since almost all of the arguments in dll function are typedefined as WORD, short and struct et al, I hope you could give me some hints on it.
Thank you very much sincerely!
Kang
Depending on the actual C implementation you can simply create a LabVIEW enum with the according item names or use a ring control instead. Teh enum requires the numeric values of the items to be in consecutive order without any gaps in between. This is a given if the C definition never assigns a specific number to the item. If the C enum is not consecutive you need to go with a ring control instead.
Rolf Kalbermatter
CIT Engineering Netherlands
a division of Test & Measurement Solutions