NI-1394 and HP1437A A/D card compatability

[nk 546]

I was using my HP1437A card successfully with the MXI-2 controller, which allowed a shared PC RAM access. The NI-1394 doesn't, and I think that may be my problem. Everytime I attempt to read data using the 1394, my computer freezes.

Has anyone ever used the NI-1394 VXI controller with VXI A/D boards?
Is the NI-1394 VXI controller generally used with VXI A/D boards? Or is it used just with VXI-Tuners, switches etc...? Or is it just my HPE1437 board that requires shared memory access, and isn't compatabile.

Thank you for any information,
Nandeesh

[Julianna]

Hello Nandeesh!

I looked up the HP E1437A on the Agilent site. Since it does not have bus master capability, shared memory is not an issue. You mention that when you try to read data using the VXI-1394 interface your computer freezes. When this happens, what do you observe? Is it a hard freeze where you have to reboot the computer? Or is it only the application that freezes? What OS and version of NI-VXI and NI-VISA are you using on that system? Do all VXI functions cause the freeze, or are there only certain ones (and which ones)? Does turning off the VXI chassis un-freeze the computer (even if it returns an error)?

What environment is your application developed in? Does it use NI-VXI functions or VISA? The VXI-1394 interface has much slo
wer performance than the MXI-2 for most types of data transfers. Could this performance difference affect the program? For example, trying to read data from the instrument before the previous function has finished? The VISA Interactive Control utility allows you to send commands interactively (write a command, read data, etc) to help troubleshoot the issue.

[nk 546]

Thank you so much for the quick response!

I'm a beginner into the VXI world so why does "HP E1437A not having bus master capability make shared memory not a compatability issue. Is shared memory defined when the controller allocates more than one address space (A24 or A32)?

I'm using Windows 2000 Service Pack 2, NI-VXI version 3.2, with a Visual Basic SP 6 environment.

The HP E1437A has a driver for programming. You don't
need to send NI-VXI functions directly. The user programms the board through it's DLL.

The crash that I spoke of, was a hard freeze that forced me to reboot the computer. While programming the HP E1437A, all functions worked properly, accept
for the hp1437A_read command, which froze the computer.
In some cases when turning off the
VXI chassis, the computer remained frozen and than switched to a blue screen and started a memory dump.

In the NI-VXI 3.2 read me file it says the following:

5.4.3.
----------------------
There is a known bug that prevents a certain sequence of actions using
VXI-1394 shared memory. From an external bus master, when doing a read from
an address, and then a write and a read to a consecutive address, the written
data will not be returned in the second read. Instead, the original value in
that location will be returned. However, the data has actually been written
into the shared memory location. If you do a subsequent read from the same
location, the written data will show up correctly. Note that this refers to
sharing host (workstation) RAM. You cannot share on-board RAM on a VXI-1394.
------------------------

This could be a problem.
Thank you,
Nandeesh

[Julianna]

Hello Nandeesh,

Since we do not know how the HP driver was implemented, I would like for you to run NI-Spy to capture the function calls the driver makes. NI-Spy is most likely located at Start -> Programs -> National Instruments on your computer. Here is a link to information on NI-Spy:
http://www.ni.com/support/vxi/spy/spy.htm

Under the Spy -> Options... menu, select to log to file as described in the above web page. Since your computer is freezing at the read function, you should select fail-safe logging. Then start the Spy capture, and run your program. Please send me the resulting .spy file, and we may be able to have a better understanding of why the computer freezes at this point.

Thanks!
Julianna

[nk 546]

hi!

I'm sending you the capture.spy file I created when testing the HP board. It freezes at the viMove command
where the HP E1437A read command executes.

Thanks again
Nandeesh

[nk 546]

Here's another capture file containing the looged commands using the MXI-2 NI controller.

[nk 546]

Hello,

The procedure on both capture files were the same. HP has a small Software Front Panel example that tests it's A/D card. I ran the example on both systems (MXI-2 and the NI-1394) with the NI-Spy running. The example basically controls the A/D card (performs the read command)and displays the sampled data graphically.

The NI-1394 version tends to perform a series of pokes and peeks before executing the viMove command.
The MXI-2 version clearly initializes the card and than lets the HP E1437A DLL control the card.

Thank for the help,
Nandeesh Kumar

[nk 546]

I have disabled one of the processors on my mulit-processor mother board and still found the same error.
I carefully checked system info to verify whether one or two processors were running.

I've attached the capture file for the test using one processor and the NI-1394 controller

Thanks
Nandeesh