If your application traps when calling an external DLL, follow these steps as you look for the error:

•Check the ESL error log and the function return value for any error codes or messages.

•Make sure that you are using the correct C and ESL data types.

•If you are calling into the Windows API, use SPYXX.EXE to examine what the function is sending to the window.

•Call the same function from a DLL or a C executable and compare what it sends to the window with what the ESL call sends.

•Create a DLL that uses the same data types. Include the function “DebugBreak();”, which will enable the Visual Studio debug tool to be accessed when the DLL is called from ESL. Compile and Link the DLL using the debug options, then examine what the function receives by using Visual Studio.

Make sure you have prototyped your external functions correctly for use with ESL.