Error Code 1097 Coming in DLL Calling

Question

Hi,
I am getting error code 1097 in DLL calling function. Please find the DLL calling function details for more information.
Function :  GetControllerListTest(controller *ptrControllertest,char *max_controller);
Controllertest parameter details:
define NO_OF_CONTROLLER  100
#ifndef CONTROLLER_STRUCT
 typedef struct
  CString name;
  char status;
  CString blocked_by;
  char group;
 }controller;
Controllertest parameter data type is structure. In LabVIEW, I have configured parameter as a cluster.
name : String control
status : U8 Integer control
blocked_by : String control
group : U8 Integer control
Could you please confirm it, did I configured the datatype in correct way?
I am getting empty array output and Error Code from the DLL 1097. Can you please tell me where I am missing?
Thanks
Sivaramkumar.V
Solved!
Go to Solution.

Answer 1

Call Library Node problems without the VI in question attached AND the complete C prototype of the function provided, AND preferably some documentation about the C function in question can be not diagnosed. These informations are paramount to get the Call Library Node configured properly since there is no way a calling application can retrieve the necessary information from the DLL itself. The DLL interface was never intended to be a self configuring interface and it was designed with the understanding, that the user of such an interface is a fully knowledgeable C programmer knowing both, how to read a header file definition as well as various details about memory buffer handling.
So show us your VI and the C header file, and we can start to help you. Otherwise all we can do is guessing in the way you have done with changing the calling convention randomly. You can of course try to shoot in the shooting range with a blindfold on, but the chances that you not only do not hit the target, but injure some other person instead is very high.
The only reason that the suggestion from Fragger Fox has any merits is the fact that LabVIEW used to have some heuristics that changed the Call Library Node automatically from C calling convention (the LabVIEW default) to Windows calling convention, if it recognized a certain pattern in the exported function name. This heuristic was removed in LabVIEW 2009 because it did prevent the Call Library Node to be able to call functions that were using C calling convention but happened to match the heuristic pattern. So changing a Windows calling convention to C calling convention when the code has "seemed" to work before is NEVER a solution.
Rolf Kalbermatter
CIT Engineering Netherlands
a division of Test & Measurement Solutions