So I've now progressed to having an almost functioning wrapper.
Other posts regarding my wrapper issues are:
http://stackoverflow.com/questions/2430089/c-wrapper-and-callbacks &
http://stackoverflow.com/questions/2444687/c-wrapper-for-array-of-three-pointers
I use the wrapper to establish a connection to the Dallmeier using the following:
_dallmeier.SessionHandle = DallmeierSDK.dlm_connect(_handle, _ip, "", _pass, null, null, connectionCallback, pInPut)
This returns the session handler. After awhile I get a AccessVoilationException about attempted to read or write protected memory.
I think this has something to do with using Marshal.Read and/or Marshal.Copy (as stated in one of the posts above) but I'm not sure where I use these commands.
Can some please advise me on this and/or examples?