cDAQ-9189 Theory of Operation
- Updated2024-12-11
- 3 minute(s) read
cDAQ-9189 Theory of Operation
The cDAQ-9189 eight-slot Ethernet chassis is designed for use with C Series modules. The cDAQ chassis are capable of measuring a broad range of analog and digital I/O signals and sensors.
The cDAQ-9189 is a CompactDAQ Ethernet chassis designed for distributed sensor measurement systems. The chassis controls the timing, synchronization, and data transfer between C Series I/O modules and an external host. With this chassis, you can combine C Series I/O modules to create a mix of analog I/O, digital I/O, and counter/timer measurements. The chassis provides precise, synchronized timing over the network using TSN, ideal for highly distributed measurements over long distances. The chassis also has four 32-bit general-purpose counters/timers, accessible through a hardware-timed digital C Series module for applications that involve quadrature encoders, PWM, pulse train generation, and more.
cDAQ-9189 Block Diagram
cDAQ Chassis Components Overview
The cDAQ system consists of three parts: C Series module(s), the cDAQ module interface, and the NI ASIC used by the cDAQ-9189.
These components digitize signals, perform D/A conversions to generate analog output signals, measure and control digital I/O signals, and provide signal conditioning.
C Series Module
National Instruments C Series modules provide built-in signal conditioning and connectivity, such as screw terminal, spring terminal, BNC, DSUB, or RJ-50 connectors. A wide variety of I/O types are available, allowing you to customize the cDAQ system to meet your application needs.
C Series modules are hot-swappable and automatically detected by the cDAQ chassis. I/O channels are accessible using the NI-DAQmx driver software.
Because the modules contain built-in signal conditioning for extended voltage ranges or industrial signal types, you can usually make your wiring connections directly from the C Series modules to your sensors/actuators. In most cases, the C Series modules provide channel-to-ground and channel-to-channel isolation.
For more information about which C Series modules are compatible with the cDAQ chassis, go to ni.com/r/cdaqenet.
cDAQ Module Interface
The cDAQ module interface manages data transfers between the NI ASIC and the C Series modules. The interface also handles autodetection, signal routing, and synchronization.
NI ASIC
The NI ASIC used in the cDAQ-9189 features independent high-speed data streams; flexible AI, AO, and DIO sample timing, triggering, flexible counter/timers with hardware gating, digital waveform acquisition and generation, and static DIO.
- AI, AO, and DIO Sample Timing—The cDAQ-9189 ASIC
contains advanced AI, AO, and DIO timing engines. A wide range of timing and
synchronization signals are available through digital I/O modules. Refer to the
related topic links below for more information about the configuration of these
signals.
- Analog Input Timing Signals
- Analog Output Timing Signals
- Digital Input Timing Signals
- Digital Output Timing Signals
- Triggering Modes—The cDAQ chassis supports different trigger modes, such as start
trigger, reference trigger, and pause trigger with analog, digital, or software
sources. Refer to the related topic links below for more information about the
configuration of these signals.
- Analog Input Triggering Signals
- Analog Output Triggering Signals
- Digital Input Triggering Signals
- Digital Output Triggering Signals
- Independent Data Streams—The cDAQ chassis supports seven independent high-speed data streams, which allow for up to seven simultaneous hardware-timed tasks, such as analog input, analog output, buffered counter/timers, and hardware-timed digital input/output.
- Flexible Counter/Timers—The cDAQ chassis includes four general-purpose 32-bit counter/timers that can be used to count edges, measure pulse-widths, measure periods and frequencies, and perform position measurements (encoding). In addition, the counter/timers can generate pulses, pulse trains, and square waves with adjustable frequencies. You can access the counter inputs and outputs using parallel digital I/O modules installed in up to two slots. Refer to the Using Counters section for more information.
In This Section
Related Information
- Analog Input Timing Signals
The cDAQ chassis features the following analog input timing signals.
- Analog Output Timing Signals
The cDAQ chassis features the following AO (waveform generation) timing signals.
- Digital Input Timing Signals
The cDAQ chassis features the following digital input timing signals.
- Digital Output Timing Signals
The cDAQ chassis features the following DO timing signals.
- Analog Input Triggering Signals
A trigger is a signal that causes an action, such as starting or stopping the acquisition of data. When you configure a trigger, you must decide how you want to produce the trigger and the action you want the trigger to cause. The cDAQ chassis supports internal software triggering, external digital triggering, analog triggering, and internal time triggering.
- Analog Output Triggering Signals
A trigger is a signal that causes an action, such as starting or stopping the acquisition of data. When you configure a trigger, you must decide how you want to produce the trigger and the action you want the trigger to cause. The cDAQ chassis supports internal software triggering, external digital triggering, analog triggering, and internal time triggering.
- Digital Input Triggering Signals
A trigger is a signal that causes an action, such as starting or stopping the acquisition of data. When you configure a trigger, you must decide how you want to produce the trigger and the action you want the trigger to cause. The cDAQ chassis supports internal software triggering, external digital triggering, analog triggering, and internal time triggering.
- Digital Output Triggering Signals
A trigger is a signal that causes an action, such as starting or stopping the acquisition of data. When you configure a trigger, you must decide how you want to produce the trigger and the action you want the trigger to cause. The cDAQ chassis supports internal software triggering, external digital triggering, analog triggering, and internal time triggering.
- Using Counters
The cDAQ chassis has four general-purpose 32-bit counter/timers and one frequency generator.