DAQPad 6508 (usb) crashes if i read data too fast

[Hengy]

I get a severe crash if i try to repeatedly read digital input using traditional daq read port on a daqpad 6508 (usb). If i put a delay of 200 ms then it works ok, so long as i re-initialise the port on each read. if i try to read faster then the daq6508 stops responding, and i need to reboot to get max to see the card again. On a two occasions this has led to a severe crash, which has trashed my MAX database and required a reinstall.

Any clues as to why i can't read a port more rapidly than 200ms

[JonBowers]

Hi Hengy,

What version of Traditional NI-DAQ  and LabVIEW (or other ADE) are you using? Is it posible to post some code that has caused this crash? Have you tried using the Intermediate vi's to perform this read (DIO Config.vi and the DIO Read.vi). This way you make sure you are not initialising the device each time you want to read from it.

Regards

Jon B
Applications Engineer
NI UK & Ireland  

[Hengy]

Jon,

Thanks for the reply, i'm using labview 8.2.1 and the latest max + traditional nidaq support.

I got round the problem by setting up the daqpad to run in a handshaking mode, using the c ports and a trigger line and thereby got round any need to rapidly poll line states on the interface. Also  ensuring the interface was only initialised once and then left running helped (using advanced io vi's). It now seems to be able to handle transfers at the not particuarly fast 100 ms that i require. Also stability was improved (slightly) by not connecting the daqpad through a usb hub.

Message Edited by Hengy on 07-04-2007 03:57 AM