National Instruments VXI-MIO Series - Manual (Page 43)

Chapter 3 Hardware Overview
VXI-MIO Series User Manual 3-14  National Instruments Corporation
In low-hysteresis analog triggering mode, the trigger is generated when
the signal value is less than lowValue, with the hysteresis specified by
highValue.
Figure 3-8. Low-Hysteresis Analog Triggering Mode
The analog trigger circuit generates an internal digital trigger based on
the analog input signal and the user-defined trigger levels. This digital
trigger can be used by any of the timing sections of the DAQ-STC,
including the analog input, analog output, and general-purpose
counter/timer sections. For example, the analog input section can be
configured to acquire n scans after the analog input signal crosses a
specific threshold. As another example, the analog output section can be
configured to update its outputs whenever the analog input signal
crosses a specific threshold.
Digital I/O
The VXI-MIO Series modules contain eight lines of digital I/O for
general-purpose use. You can individually configure each line through
software for either input or output. At system startup and reset, the
digital I/O ports are all high impedance.
The hardware up/down control for general-purpose counters 0 and 1 are
connected onboard to DIO6 and DIO7, respectively. Thus, you can use
DIO6 and DIO7 to control the general-purpose counters. The up/down
control signals are input only and do not affect the operation of the DIO
lines.
highValue
Trigger
lowValue