Hi. I had this problem too. Spent nearly a whole week trying to resolve it.
I was aquiring analogue data on multiple channels over multiple cards with synchronous clocks.
I eventually solved it by setting the chart max, min, and increment properties ia a property node. I could do this becuase I had to use finite samples in the aquisition. Max = max sample no., min=0, increment=dt
Hope this helps.
sampledout