I'm using a PCI MIO 16XE50 and an SCB68 with LV 8 to generate pulses signals to a stepper motor controller. I'm using the Labview generate pulse vi and the rise and fall time of the pulses is not correct. Information on the NI web site says that the rise and fall time should be less than 50 ns. My pulses drop from 5 V to 2.5 V, stay at 2.5 V for 250 ns, then fall. Same profile on the rising edge. This seems to happen either with the counters or the digital lines. I think this is causing the stepper controller to see two falling edges because it often makes two moves instead of one.
Is the 250 ns pause normal for this hardware? Is there some calibration or setting that needs to be adjusted?