The action would be stopped regardless of the infinite setting when the E series of analog board is used.
The E series of analog board doesn't feature the infinite sampling function, the driver uses the external trigger stop mode instead of the infinite sampling function.
Therefore, input the trigger to External Stop Trigger pin during converting and then the conversion is stopped.
For avoiding this question, please short-cut External Stop Trigger pin and Digital Ground.
E series of analog board
AD12-16(PCI)EV
AD12-16U(PCI)EV
AD16-16(PCI)EV
AD16-16U(PCI)EV
AIO-121601E3-PE
AIO-121601UE3-PE
AIO-161601E3-PE
AIO-161601UE3-PE