Can multiple 1394 Controllers be switched in and out of operation and configured correctly?

Question

The test system I'm working on has a 'core' VXI System using a Slot-0 1394 Controller that is always powered up but also requires other systems to be switched in and out as required under the control of LabVIEW 7.1 software. The interface to all of the VXI systems is made via PCI Firewire interface to the single controlling PC.
The test system needs to be able to perform various sequences of actions using multiple peripheral systems but always with the 'core' system powered up. An example sequence would be:
1) Power up the 'core' VXI system and communicate with the instruments
2) Power up  peripheral VXI system '1' and communicate with the instruments
3) Power down  peripheral VXI system '1' 
4) Power up  peripheral VXI system '2' and communicate with the instruments
5) Power down  peripheral VXI system '2'
6) Power down the 'core' VXI system
In order to simulate the above sequence of actions in a test environment I have two VXI Chassis systems and three Slot-0 Controllers which I have attempted to use as follows:
1) Power up VXI Chassis 1 and communicate with the instruments
2) Power up peripheral VXI Chassis 2 and communicate with the instruments
3) Power down  VXI Chassis 2 and replace the Slot-0 Controller 
4) Power up VXI Chassis 2 with the new Slot-0 Controller and communicate with the instruments
5) Power down VXI Chassis 2
6) Power down VXI Chassis 1
I have registered all of the Slot-0 Controllers in MAX beforehand and they are persistent and appear as VXI systems '0'-'2' in the GUI.
I have run resman programmatically in LabVIEW 7.1 (using NI-VXI 3.3.1 and the suggested patch) using a command line of "resman -b'n' -o" (where 'n' is the system number) in order to run the executable silently (which will be required for the completed test system). Resman is run after the power up of each chassis (for that VXI system only) in steps 1 and 2 and works ok at these stages. When resman is run after the power up in step '4' however, resman crashes along with LabVIEW.
As an extra test I tried just attempting to 'find' each of the systems using the 'VISA find resource' VI after the power-up of each VXI system but without performing any other actions (i.e. running resman or communicating with the instruments). For steps 1 and 2 this also works ok but in step 4 this again results in a fatal crash in LabVIEW. 
Could you tell me if these crashes are to be expected or if I am doing something wrong?
thanks
Lee Hutchinson
Test Software Engineer
BAE Systems
Waterlooville
Hants

Answer 1

Hi Lee,
In the VXI-1394 User Manual we say that you should always have VXI unit powered up before the PC. I think this would go for peripheral VXI units as well. For this system to work stabley I would have thought that you need to power up the peripheral VXI chassis, then the core then the PC.  The way you are doing it at the moment you are effectively replacing one 1394 controller with another and I don't think the PC will be able to handle the references to them in this manner.
Regards
Jon B
Applications Engineer
NIUK