Hi there,
I had recently trying to compile my working 32bit Labview application to 64bit since I want to try out the performance under 64bit OS. 32bit application is noticably slow on a 64bit OS.
Here is my problem: I am using VISA Write Function in the application and for some reason, I am getting errors back when I run the 64bit application but the same code run on 32bit application.
I tried NI VISA 5.4 & 14.0 but both throwing errors. Anything else I can do to eliminate the error here? 
Below are output from the NI IO Tracer:
32bit:
200. VISA Write ("GPIB0::18::INSTR", "*IDN?")
Process ID: 0x000008E4 Thread ID: 0x000017FC
Start Time: 22:29:06.944 Call Duration 00:00:00.015
Status: 0 (VI_SUCCESS)
201. VISA Get Attribute ("GPIB0::18::INSTR", 0xBFFF0002, "GPIB0::18::INSTR")
Process ID: 0x000008E4 Thread ID: 0x000017FC
Start Time: 22:29:06.960 Call Duration 00:00:00.000
Status: 0 (VI_SUCCESS)
202. VISA Get Attribute ("GPIB0::18::INSTR", 0x3FFF001A, 3000)
Process ID: 0x000008E4 Thread ID: 0x000017FC
Start Time: 22:29:06.960 Call Duration 00:00:00.000
Status: 0 (VI_SUCCESS)
64bit:
9. VISA Write ("GPIB0::18::INSTR", "*IDN?")
Process ID: 0x00000A74 Thread ID: 0x00001150
Start Time: 21:08:25.491 Call Duration 00:00:00.005
Status: 0xBFFF0011 (VI_ERROR_RSRC_NFOUND)
10. viParseRsrc (0x00001002, "GPIB0::18::INSTR", 1, 0)
Process ID: 0x00000A74 Thread ID: 0x00001150
Start Time: 21:08:25.496 Call Duration 00:00:00.001
Status: 0 (VI_SUCCESS)
Thanks!