VME control using Lab Windows and VME-MXI-2

[AlanKnowler]

Help! I need to do the following from Lab Windows CVI:
1) set the VME control signals SYSRESET and ACFAIL to both logic 1 and 0.
2) read/write memory addresses from the VME memory map.

I've not used VME before, and these don't look like trivial tasks. The VME rack is fitted with a VME-MXI-2 card and the PC is fitted with a PCI-MXI-2 card. If anyone has had experience of this before and pointers would be very useful. (I can't find much on the NI web site)
Thanks Alan

[Greg Caesar]

Alan,


As for reading and writing memory addresses from the VME memory map, you could use functions such as viIn8, viIn16, viIn32, viOut8, viOut16, or viOut32 in the NI-VISA API. You can find the NI-VISA Funtion help at "Start >> Programs >> National Instruments >> NI-VISA >> NI-VISA Help" for Windows. Alternativelly, the NI-VISA Programmers Reference Manual is available for download from ni.com.

What exactly is your application that uses ACFAIL? ACFAIL is typically pretty unrealiable, and is a difficult signal to catch (especially over a bus extension like MXI-2). Basically, ACFAIL is asserted right before a total failure/shutdown of the chassis, so you have a very short window of time to detect the signal before it disappears.


Regards,
Greg Caesar
App
lications Engineer
National Instruments

[AlanKnowler]

Thanks for the memory map bits - accessing VME address space is starting to become clear.

The scenario is this: We are testing a card whose ultimate destination is in a VME rack. We need to be able to switch the signals acfail and sysreset to '1' and '0' independently and verify that the card performs as we expect. I do not need to catch either acfail or sysreset.