National Instruments Eight-slot USB Chassis NI cDAQ-9172 - Manual (Page 19)

© National Instruments Corporation 19 NI cDAQ-9172 User Guide and Specifications
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Correlated vs. Static DIO Modules
Digital I/O module capabilities are determined by the type of digital signals
that the module is capable of measuring or generating. Static digital I/O
modules are designed for signals that change slowly and are accessed by
software-timed reads and writes. Correlated digital I/O modules are for
signals that change rapidly and are updated by either software-timed or
hardware-timed reads and writes. For more information about Digital I/O
modules, refer to the
Digital I/O section.
cDAQ Module Interface
The cDAQ Module Interface manages data transfers between the
USB-STC2 and the C Series I/O modules. The interface also handles
autodetection, signal routing, and synchronization.
USB-STC2
The USB-STC2 features independent high-speed data streams; flexible
AI and AO sample timing; triggering; PFI signals for multi-device
synchronization; flexible counter/timers with hardware gating; digital
waveform acquisition and generation; and static DIO.
AI and AO Sample Timing
The USB-STC2 contains advanced analog input and analog output timing
engines. A wide range of timing and synchronization signals are available
through the PFI lines. Refer to the
Analog Input Timing Signals and
Analog Output Timing Signals sections for more information about the
configuration of these signals.
Triggering Modes
The NI cDAQ-9172 supports different trigger modes, such as start trigger,
reference trigger, and pause trigger with analog, digital, or software
sources. Refer to the
Analog Input Triggering and Analog Output
Triggering sections for more information.
Independent Data Streams
The NI cDAQ-9172 supports four independent high-speed data streams;
allowing for up to four simultaneous hardware timed tasks, such as analog
input, analog output, buffered counter/timers, and correlated digital
input/output.