I would suggest that you try the DAQ Diagnostic Utility available here:
If this test passes the analog input test you might have a problem with your SCB-68. If you are using the 6224 you should have two connector blocks (two SCB 68s). Have you tried your second SCB-68?
If DAQ Diagnostic Utility reports any failures, or if you have tried the 6224 with different cables, and different SCB-68s the only other test you could try would be to put the card in another machine. If all of these tests fail, you probably have a problem with your card. If you would like to talk to a customer service representative about having your card repaired you can call (800) 531-5066.
Message Edited by Jesse O on 03-03-2006 02:05 PM