Instacal keeps losing my board information

[jopublic]

I am using Meilhaus Elec software to set up and calibrate four boards that i am using to log data and control eqipment via a labview programm i have written. However, after i have set up the four boards (2x USB-TC, 1x USB-3104 and 1xUSB-1208F) using Instacal and then run the labview programme, the programme only runs for a few seconds then crashes. After the crash when I go back to Instacal some of the boards are missing or the board numbers have changed. Theni have to re-start the PC otherwise Instacal can no longer find the boards.

I have the four boards routed through a USB hub and then taking a single USB connection back to the PC. The PC is a HP with 2 GB RAM and a dual-core processor and when I run the labview programme without the boards attached it works fine.

Do you know of a reason why Instacal keeps losing the board information and connections?  Or is there some known conflict when using it with Labview that could explain the problems I am experiencing.

Any suggestions will be appreciated.

Regards

Trevor Morgan (Imperial College London).

[J-M · Accepted solution]

It is possible to post your code? What did you mean by the program crashes?  Did  you received the error code “1-  Invalid board number” (ErrHdlng.VI from MCC)?   I have a LabVIEW program with four MCC boards: a USB-TC, a USB-3103, a USB-SSR24 and a USB-ERB24.  When I used a USB-HUB, sometime I lost the communication with a board, but after hours not after few seconds (I removed the USB-HUB).  Without the HUB the program runs for days.

Jean-Marc

[jopublic]

Thanks for your comments.

It seems that the PC or Instacal can't cope with 4 boards connected through a USB hub. On the advice of Melihaus Elec. i have limited my USB connections to 2 per port and this has solved the problem. The progamm nows runs without crashing.

It is also interesting to note that when i ran the programm on two older PC's it worked fine with all 4 boards connected to one port.