how to program with different device by NI-VISA?

[east]

Dear NIer:
firstly I will list my enviroment.
SW:Labwindows/cvi 5.5/VISA/MAX.
HW:HP pc/pci-gpib/GPIB-VXI/DD42916.
QUESTION:
1 MAX always think GPIB-VXI/C and DD42916 as a GPIB device.Why don't they think these devices listed above as a VXI device?

2 Since MAX think DDC42916 as a GPIB device, and DDC42916 supports word serial communication, How can I program with this message-based device by NI-VISA?
I searched for appropriate function in NI-VISA ref manual,but I failed.VXI WSPRotocal COMMand is not suitable here evidently.

3 Then how can I program the other device like register-based device and memory-based device under this circumstance?

4 if slot0 controller changed from GPIB/VXI to 1394/
VXI,then how to program?

[Dan_Mondrik]

You need to do 1 of 2 things to make MAX recognize the GPIB-VXI as a VXI controller:
1) Make the GPIB-VXI primary address 1 (which it should be as the factory default)
2) Right-click on Devices&Interfaces and create a new GPIB-VXI. Tell MAX the information it needs to know the location of the GPIB-VXI (usually GPIB board 0, primary address 1, secondary address 0).

Then there should be a GPIB-VXI entry that shows up in MAX. You can program the device as a VXI device. If the DDC42916 is at logical address 8, for example, the string would be GPIB-VXI0::8::INSTR. If you change to a VXI-1394 controller, then the only programming change would be to use VXI0::8::INSTR.

Regardless of which controller you use, the register based functions in VISA should work
fine once the controller is correctly identified in MAX. Just remember that there are hardware limitations of the GPIB-VXI such as no D32 support, no A32 support, no VXI interrupts other than SRQ (REQT), etc. These are limitations due to the nature of the hardware architecture, not the software.

By the way, to send a miscellaneous word serial command, use viVxiCommandQuery.

Hope this helps.

Dan Mondrik
Senior Software Engineer, NI-VISA
National Instruments