PCI Device Detection Order

[slartibardfast]

Hi All,

I am investigating device detection order in relation to multiple M-Series DAQ Cards (NI-6229).

Specifically in the case installing two DAQ Cards in PCI slots connected to slots on a secondary PCI bridge,
the order of detection seems to be inverted e.g. first slot detects as Dev2, second slot detects as Dev1.

This poses a problem because I need to rely on Dev1 being physically below Dev2.

In the case of using a PCI slots on the primary PCI bridge or one slot on the primary PCI bridge and a slot on the secondary PCI bridge the device detection order works as expected.

Can anybody explain what logic is used to detect the order of DAQ Cards in the NI-DAQmx 7.4 series of drivers?
I realize the installation guide somewhat recommends not using DAQ cards in anything other than the primary PCI bridge,
however I need the flexibility of all PCI slots being available.

TIA.

-David Connolly

[JamesC]

Hi David,

Device enumeration is not handled by NI Drivers, but rather by the Motherboard setup, and the OS. In windows from Win 98/2000 onwards, this was handled with ACPI, which also delas with the different power down states and recovery from these states.

Please review the following links. Win ACPI and also Solving PCI IRQ Problems please look at the PCI detection order section.

Hope this information answers your questions.

Regards
JamesC
NIUK and Ireland

[slartibardfast]

Hi James,
                Ah that explains it, thanks for the links.

-dc