We have our own made VXI data acquisition board. However sometime these boards are not found by the resman. We pull out the devices and reseat the board, sometimes that will be OK. But after a while it may happen again. Any ideas on that?
Resman works by querying the A16 space where each device from Logical Address 0 - 255 should have its configuration registers. If Resman does not get a response when querying a range, it won't detect a device there. If you have a VXI bus monitor, I'd ensure your device is responding. Also, VXI spec only requires that Resman can be run once after powerup. Does cycling power change the behavior?
What happens is it is finn today. Next day those devices are not recognized after power on. We have to pull out the devices and inserted them again. Sometimes we have to repeat this process several times to get them recognized. We are frustrated. BTW, how can I get a bus monitor? How much does it cost? Thanks for the help.
It depends if you want a bus monitor or a logic analyzer. If you just want to see the signals on the address pins, something like this probe might work to get to the signals easily. Otherwise, you could look at a VXI bus analyzer such as those offered by VMEtro.
You could also try consecutive reads into A16 space where the configuration registers for your device should reside. You can do this even if the device doesn't show up after Resman by opening a session to MEMACC and doing a read. This might be an easier way to see if the device is sporadically not responding to accesses.
Have you verified that the controller is working properly by swapping out other controllers?
Another comment: You also want to ensure that only one device in the system is driving the VXI Bus Timeout signal. Also, ensure that in MAX your VXI Bus Timeout is set high enough to give time for your device to respond. You can change this by right-clicking on the VXI system and choosing Hardware Configuration.