Chapter 3
Hardware Overview
PCI-MIO E Series User Manual
3-16
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National Instruments Corporation
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 PCI-MIO E Series boards contain eight lines of digital I/O for
general-purpose use. You can individually software-configure each line
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.
Timing Signal Routing
The DAQ-STC provides a very flexible interface for connecting timing
signals to other boards or external circuitry. Your PCI-MIO E Series
board uses the RTSI bus to interconnect timing signals between boards,
and the Programmable Function Input (PFI) pins on the I/O connector
to connect the board to external circuitry. These connections are
designed to enable the PCI-MIO E Series board to both control and be
controlled by other boards and circuits.
There are a total of 13 timing signals internal to the DAQ-STC that can
be controlled by an external source. These timing signals can also be
controlled by signals generated internally to the DAQ-STC, and these
selections are fully software configurable. For example, the signal
routing multiplexer for controlling the CONVERT* signal is shown in
Figure 3-11.
