NI-DAQmx FAQ Answers and User Manual Assistant

What is NI-DAQmx?

NI-DAQmx is the driver software used to communicate with and control NI data acquisition (DAQ) devices.

Manual reference: NI-DAQmx Overview, p. 27

What is the difference between NI-DAQmx and Traditional NI-DAQ?

Who Must Use Traditional NI-DAQ (Legacy) Install and use Traditional NI-DAQ (Legacy) if one of the following situations apply: Simpler, more intuitive APIs for creating DAQ applications using fewer functions and VIs than earlier versions of NI-DAQ.

Manual reference: Measurement Studio., p. 273

What types of measurements can NI-DAQmx perform?

Strain gage rosettes are used to perform such measurements. Full-Bridge Type III Circuit Diagram

Manual reference: Full-Bridge Type III Circuit Diagram, p. 621

How do I use NI-DAQmx with LabVIEW?

Use this workflow from the manual:

1. If you program your NI-DAQmx-supported device in LabVIEW, you can interactively create virtual channels—both global and local—and tasks by launching the DAQ

Manual reference: LabVIEW; LabVIEW require properties. ANSI C and LabWindows/CVI employ the Get and Set, pp. 29, 75

How do I use NI-DAQmx with LabWindows/CVI?

Use this workflow from the manual:

1. ANSI C and LabWindows/CVI employ the Get and Set

Manual reference: LabVIEW require properties. ANSI C and LabWindows/CVI employ the Get and Set; How does DAQmx Work Together with Other Applications and, pp. 75, 28

How do I use NI-DAQmx with Measurement Studio?

Use this workflow from the manual:

1. NET, select Measurement Studio»NI

Manual reference: Measurement Studio with Visual C++, Visual C#, or Visual, p. 30

How do I use NI-DAQmx with ANSI C?

Use this workflow from the manual:

1. Add the NI-DAQmx import library, nidaqmx.lib, to the project. The import library files are located under NI-DAQ\DAQmx ANSI C Dev\lib\.
2. To view examples of NI-DAQmx applications, go to the NI-DAQ\Examples\ DAQmx ANSI C directory.

Manual reference: DAQmx ANSI C directory., p. 31

How do I use NI-DAQmx with SignalExpress?

SignalExpress If you use your NI-DAQmx-supported device in SignalExpress, you can create a project that includes NI-DAQmx steps. With SignalExpress, you can log and analyze data.

Manual reference: For help with using the DAQ Assistant with Visual Studio .NET, refer to Using NI-DAQmx, p. 32

How do I get started with NI-DAQmx?

Each API includes a collection of programming examples to help you get started developing an application. Getting Started with NI-DAQmx The Getting Started with NI-DAQmx series on ni.com helps you learn NI-DAQmx programming fundamentals.

Manual reference: Getting Started with NI-DAQmx, p. 33

What does the Getting Started with NI-DAQmx series cover?

To access the series, go to Getting Started with NI-DAQmx on ni.com. The Getting Started with NI-DAQmx series on ni.com helps you learn NI-DAQmx programming fundamentals.

Manual reference: Getting Started with NI-DAQmx; How does DAQmx Work Together with Other Applications and, pp. 33, 28

How do I verify a device's operation in Measurement & Automation Explorer?

Through video and text tutorials, this series takes you from verifying your device's operation in Measurement & Automation Explorer (MAX) to programming data acquisition applications using LabVIEW. What is Measurement & Automation Explorer (MAX)? For more information, refer to the Measurement & Automation Explorer Help for NI DAQmx or Getting Started.

Manual reference: Getting Started with NI-DAQmx; NI-DAQmx Overview, pp. 33, 27

Can I run NI-DAQmx examples without hardware installed?

To run examples without hardware installed, you can use an NI-DAQmx simulated NI-DAQmx Software and Hardware Installation

Manual reference: Getting Started with NI-DAQmx, p. 33

What is an NI-DAQmx simulated device?

NI-DAQmx tasks using NI-DAQmx simulated devices are verified just as tasks are on physical devices.

Manual reference: Task Behavior of NI-DAQmx Simulated Devices, p. 265

How do simulated devices behave in NI-DAQmx?

Task Behavior of NI-DAQmx Simulated Devices NI-DAQmx tasks using NI-DAQmx simulated devices are verified just as tasks are on physical devices. If a property is set to an invalid value, the error returned for an NI DAQmx simulated device is identical to the error returned for a real device.

Manual reference: Task Behavior of NI-DAQmx Simulated Devices, p. 265

How do timing and triggering work with NI-DAQmx simulated devices?

Task Behavior of NI-DAQmx Simulated Devices NI-DAQmx tasks using NI-DAQmx simulated devices are verified just as tasks are on physical devices. If a property is set to an invalid value, the error returned for an NI DAQmx simulated device is identical to the error returned for a real device.

Manual reference: Task Behavior of NI-DAQmx Simulated Devices, p. 265

What can I configure in Measurement & Automation Explorer?

What is Measurement & Automation Explorer (MAX)? For more information, refer to the Measurement & Automation Explorer Help for NI DAQmx or Getting Started.

Manual reference: NI-DAQmx Overview, p. 27

How do I launch DAQ Assistant?

You can launch the DAQ Assistant from your NI application software or from MAX. After you launch the DAQ Assistant, follow the wizard instructions to create your new task or channel. Creating Channels and Tasks with the DAQ Assistant

Manual reference: Creating Channels and Tasks with the DAQ Assistant, p. 142

What is an NI-DAQmx task?

When Is A Task Done? If the measurement or generation is finite, the task is done when you acquire or generate the final sample or when you call the Stop Task function/VI.

Manual reference: Until Done function/VI before stopping the task. After the Wait Until Done function/VI; Task Behavior of NI-DAQmx Simulated Devices, pp. 134, 265

What is a physical channel in NI-DAQmx?

For example, if the physical channel is Dev1/ai1, the device identifier is Dev1, and the channel identifier is ai1.

Manual reference: Physical Channel Names, p. 125

What is a virtual channel in NI-DAQmx?

Virtual channels and tasks are fundamental components of NI-DAQmx.

Manual reference: NI-DAQmx Key Concepts, p. 121

What is the difference between a physical channel and a virtual channel in NI-DAQmx?

Virtual channels, or sometimes referred to generically as channels, are software entities that encapsulate the physical channel along with other channel specific information—r ange, terminal configuration, and custom scaling— that formats the data. Virtual channels are software entities that encapsulate the physical channel along with other channel specific information—r ange, terminal configuration, and custom scaling— that formats the data. Virtual channels and tasks are fundamental components of NI-DAQmx.

Manual reference: NI-DAQmx Key Concepts, p. 121

What is the difference between a local virtual channel and a global virtual channel?

Channels: Physical, Virtual, Local Virtual, and Global Virtual Virtual channels and tasks are fundamental components of NI-DAQmx. Virtual channels, or sometimes referred to generically as channels, are software entities that encapsulate the physical channel along with other channel specific information—r ange, terminal configuration, and custom scaling— that formats the data.

Manual reference: NI-DAQmx Key Concepts; DAQmx applies these attributes to the virtual channel., pp. 121, 123

How do I create virtual channels with the NI-DAQmx API?

Use this workflow from the manual:

1. You can select global virtual channels with the NI-DAQmx API or DAQ Assistant and add them to a task.
2. The following example illustrates the difference between physical and virtual channels and demonstrates how to create virtual channels with the API.
3. Specify myThermocoupleChannel as the name to assign to your virtual channel.
4. Call the AI Temp TC instance of the DAQmx Create Virtual Channel VI in LabVIEW
5. DAQ Assistant, the change applies to all tasks that use that global virtual channel.
6. Create an NI-DAQmx virtual channel to measure temperature in the range 50° C to 200°

Manual reference: DAQmx applies these attributes to the virtual channel.; DAQmx software framework to refer to the physical channel.; Creating Tasks with the API, pp. 123, 122, 129

How do I create a task with the NI-DAQmx API?

Use this workflow from the manual:

1. The following example illustrates how to create a task with the API:
2. Choosing Whether to Use the API or the DAQ Assistant
3. To explicitly start a task, call the Start Task function/VI.
4. Call the DAQmx Start Task VI (DAQmxStartTask in LabWindows/CVI).
5. Call the DAQmx Clear Task VI (DAQmxClearTask function in LabWindows/CVI).
6. How to specify this behavior depends on the operation that your task performs.

Manual reference: Creating Tasks with the API; You have now created a task called myTemperatureTask that uses a local virtual, pp. 129, 130

How do I add virtual channels to an NI-DAQmx task?

Use this workflow from the manual:

1. If you add a global virtual channel to several tasks and modify that global virtual channel with the
2. You can select global virtual channels with the NI-DAQmx API or DAQ Assistant and add them to a task.
3. DAQ Assistant, the change applies to all tasks that use that global virtual channel.
4. If you create virtual channels with the DAQ Assistant, you can use them in other tasks and reference them outside the context of a task.
5. Specify myThermocoupleChannel as the name to assign to your virtual channel.
6. Call the AI Temp TC instance of the DAQmx Create Virtual Channel VI in LabVIEW

Manual reference: DAQmx applies these attributes to the virtual channel.; DAQmx software framework to refer to the physical channel., pp. 123, 122

How do I specify physical channels in NI-DAQmx?

Use this workflow from the manual:

1. This physical channel name refers to all eight lines in a port at once.
2. Call the AI Temp TC instance of the DAQmx Create Virtual Channel VI in LabVIEW

Manual reference: Port NI-DAQmx Physical Channel Name (Lines) NI-DAQmx Physical Channel Name; DAQmx software framework to refer to the physical channel., pp. 395, 122

What is a digital line in NI-DAQmx?

Port—A port is a c ollection of digital lines. Digital lines and ports are important parts of a digital input/output system.

Manual reference: Dev1/port0:1, p. 126

What is port width in NI-DAQmx?

For Ports 0 through 3, you can configure a port width of 8, 16, or 32 bits.

Manual reference: Port NI-DAQmx Physical Channel Name (Lines) NI-DAQmx Physical Channel Name, p. 395

What are cold-junction compensation channels?

Cold-Junction Compensation Channels On devices with built-in cold-junction compensation (CJC) channels, the CJC channel is read once per sample clock edge.

Manual reference: Cold-Junction Compensation Channels, p. 128

What is a custom scale in NI-DAQmx?

Scaling, including custom scales, is not applied if PFI 0 is the trigger source.

Manual reference: Scaling, including custom scales, is not applied if PFI 0 is the trigger source. For; Prescaled Versus Scaled Units, pp. 286, 271

How do custom scales work in NI-DAQmx?

Scaling, including custom scales, is not applied if PFI 0 is the trigger source. Scaling, including custom scales, is not applied if APFI 0 or APFI 1 is the trigger source. However, if you use an analog input channel as the trigger source, you could use scaled units.

Manual reference: Scaling, including custom scales, is not applied if PFI 0 is the trigger source. For; Prescaled Versus Scaled Units, pp. 286, 271

What is the NI-DAQmx task state model?

The task state model consists of five states—Unv erified, Verified, Reserved,

Manual reference: Until Done function/VI before stopping the task. After the Wait Until Done function/VI, p. 134

What is the unverified state in NI-DAQmx?

Keep in mind that setting the value of a channel, timing, or triggering attribute/ property does not implicitly transition the task back to the Unverified state.

Manual reference: Transitioning the State Backwards, p. 141

What is the verified state in NI-DAQmx?

For example, if the task was in the Verified state and you called the Start Task function/VI to start the task, the task is reserved, committed, and started, transitioning to the Reserved state and to the

Manual reference: Transitioning the State Backwards, p. 141

What is the reserved state in NI-DAQmx?

As another example, suppose the task is in the Reserved state, and you call the Read function/VI to perform a finite measurement. For example, if the task is in the Reserved state and you set the value of timing attribute/property, the task remains in the Reserved state.

Manual reference: Transitioning the State Backwards, p. 141

What is the committed state in NI-DAQmx?

Task function/VI, the task is not just stopped and transitioned from the Running state to the Committed state. Committed state before transitioning to the Running state.

Manual reference: Transitioning the State Backwards, p. 141

What is the running state in NI-DAQmx?

Task function/VI, the task is not just stopped and transitioned from the Running state to the Committed state. Committed state before transitioning to the Running state.

Manual reference: Transitioning the State Backwards, p. 141

What are implicit task state transitions in NI-DAQmx?

Implicit Task State Transitions Although you can explicitly transition a task through each of its states as described in

Manual reference: These operations occur each time the application performs a read or write, p. 139

What happens when transitioning the task state backwards?

Transitioning the State Backwards When a task is implicitly transitioned backwards, it returns to the state of the task prior to the last operation that resulted in a forward state transition.

Manual reference: Transitioning the State Backwards, p. 141

How do I use the Start Task function or VI?

Use this workflow from the manual:

1. Call the DAQmx Start Task VI (DAQmxStartTask in LabWindows/CVI).
2. Call the DAQmx Clear Task VI (DAQmxClearTask function in LabWindows/CVI).
3. Call the DAQmx Stop Task VI (DAQmxStopTask function in LabWindows/CVI) after the desired number of samples have been acquired.
4. To explicitly start a task, call the Start Task function/VI.
5. This call implicitly starts the task, writes the single sample, and stops the task.
6. Read function/VI or a Write function/VI might implicitly start the task if one is not already started.

Manual reference: You have now created a task called myTemperatureTask that uses a local virtual; Starting a Finite Measurement Task, pp. 130, 131

What does DAQmx Is Task Done do?

Using Is Task Done When Is A Task Done?

Manual reference: Using Is Task Done, p. 133

What does DAQmx Wait Until Done do?

After the Wait Until Done function/VI executes, the finite generation has been completed, and you can stop the task.

Manual reference: Until Done function/VI before stopping the task. After the Wait Until Done function/VI, p. 134

When is an NI-DAQmx task considered done?

Until Done function/VI before stopping the task. After the Wait Until Done function/VI executes, the finite generation has been completed, and you can stop the task.

Manual reference: Until Done function/VI before stopping the task. After the Wait Until Done function/VI, p. 134

Why might an NI-DAQmx task need to be committed?

Other settings, such as the sample counter, cannot be programmed when the task is committed because they need to be programmed every time the task is started. NI-DAQmx programs some of the settings for the resources when the task is committed.

Manual reference: In certain cases, NI-DAQmx will coerce the values of attributes/properties when, p. 136

What is timing in NI-DAQmx?

A timing engine is the circuitry a device uses to control an acquisition or generation.

Manual reference: Timing engines for different devices and subsystems provide different functionality., p. 177

What is the difference between hardware timing and software timing?

You can time control loops using software timing or hardware timing. Software timing is not deterministic. Controlling a while loop and using the Wait Until Next ms Multiple VI to handle timing is an example of a software timed loop.

Manual reference: Timing Control Loops, p. 262

What is a clock in NI-DAQmx?

External clocking of the AI Convert Clock is not supported. When devices with reference clocks are in a task, you cannot set an external SampClk.Src or SampClkTimebase.

Manual reference: AI Convert Clock Considerations, p. 468

What are sample timing types in NI-DAQmx?

Each sample timing type is a different stimulus for triggering the action of producing a sample.

Manual reference: Trigger and Clock Distinction, p. 149

What is sample clock timing?

When using Sample Clock timing, all measurements returned are a valid, complete cycle of your input signal. Sample Clock Timing Support for Time-Based Measurements

Manual reference: Sample Clock Timing, p. 224

What is handshaking in NI-DAQmx?

Refer to your device documentation to see if handshaking is supported on your device.

Manual reference: Handshaking; Burst Handshaking Signals, pp. 151, 152

What are burst handshaking signals?

Burst Handshaking Signals For devices that support burst handshake timing, three signals are used:

Manual reference: Burst Handshaking Signals, p. 152

What are handshaking signals for 8255-based devices?

For 8255-based devices, the ports in the task affect which handshaking lines are used. Handshaking Signals for 8255-Based Devices

Manual reference: Handshaking Signals for 8255-Based Devices, p. 153

What is hardware-timed single point sample mode?

This mode is similar to hardware-timed single point sample mode but with slower performance and no error checking. Hardware-Timed Single Point Sample Mode

Manual reference: Hardware-Timed Non-Buffered Sample Mode, p. 476

What is the difference between multiplexed and simultaneous sampling?

When sampling a signal it is important to consider device range, input limits, sampling rate, resolution, and code width. Sampling Considerations Sampling Rate

Manual reference: Zin; Each multiplexed C Series device has a separate convert clock. The convert clock, pp. 582, 481

What are setup and hold times?

Setup and Hold Times When a DAQ device samples a digital signal, the signal must remain stable for a period of time before and after the assertion of the clock edge used for timing.

Manual reference: Setup and Hold Times, p. 156

What is simultaneous analog output on-demand timing?

Simultaneous Analog Output On-Demand Timing Typically, when you use software timing to output samples on multiple AO channels,

Manual reference: Setup and Hold Times, p. 156

What are timing response modes?

Timing Response Modes Digital I/O and DAQ devices typically use the single-cycle timing response mode, meaning the device responds to an external signal by the next active sample clock edge.

Manual reference: Setup and Hold Times, p. 156

How do I acquire a single sample in NI-DAQmx?

Single Sample Digital Input Programming Flowchart Acquiring a single sample is an on-demand operation. For example, if you periodically needed to monitor the fluid level in a tank, you acquire single data points.

Manual reference: DAQmx includes functions for timing, triggering, reading, and writing samples., p. 78

How does NI-DAQmx determine buffer size?

How Is Buffer Size Determined? If your acquisition is finite (sample mode on the Timing function/VI set to Finite For example, if you specify samples per channel of 1,000 samples and your application uses two channels, the buffer size would be 2,000 samples.

Manual reference: How Is Buffer Size Determined?, p. 192

How do continuous acquisition and generation work with a finite buffer?

Continuous Acquisition and Generation with Finite Buffer Size If you use the Timing function/VI and set the sample mode to finite or continuous, A buffer is a temporary storage in computer memory for acquired or to-be-generated samples.

Manual reference: Buffering, p. 191

How do I control where in the buffer to read samples?

Controlling Where in the Buffer to Read Samples Changing the settings of these two attributes/properties controls where in the buffer data is read. Reference Trigger, NI-DAQmx reads samples beginning with the first sample acquired with each subsequent read beginning where the previous one left off.

Manual reference: Controlling Where in the Buffer to Read Samples, p. 195

How do read status properties relate to buffers?

Read Status Attributes/Properties and Buffers The three Read Status attributes/properties are useful for observing the progress of your acquisition. The Current Read Position is the place in the buffer where the next read begins if the Relative To attribute/property is Current Read Position and the Offset is 0.

Manual reference: Controlling Where in the Buffer to Read Samples, p. 195

How do I control where in the buffer to write samples?

Controlling Where in the Buffer to Write Samples By default, NI-DAQmx writes samples sequentially beginning with the first sample in the buffer, and each write begins where the previous one left off. Space Available in Buffer is computed by first calculating the Current Write Position based on the settings of the Relative To and Offset attributes/properties and then subtracting this number from the sum of Total Samples per Channel Generated and the buffer size.

Manual reference: Controlling Where in the Buffer to Write Samples, p. 196

How do write status properties relate to buffers?

Write Status Attributes/Properties and Buffers The three Write Status attributes/properties are useful for observing the progress of your generation. The Current Write Position is the place in the buffer where the next write begins if the Relative To attribute/property is Current Write Position and the Offset is 0.

Manual reference: Controlling Where in the Buffer to Write Samples, p. 196

How do I measure voltage with NI-DAQmx?

Use this workflow from the manual:

1. Use Ohm's Law to measure voltage dropped across the load and the resistor while also converting to power.

Manual reference: Use Ohm's Law to measure voltage dropped across the load and the resistor while also, p. 51

How do I generate voltage with NI-DAQmx?

Use this workflow from the manual:

1. All the samples in the buffer are then sent to your device according to the timing you specify. You can use software or hardware timing (if your device supports hardware timing) to control when your device generates a signal.

Manual reference: Time-Varying Multiple Samples, p. 115

How do I measure current with NI-DAQmx?

You can measure current through an analog input connector. Many measurement devices can measure and generate current. To measure or generate current with a DAQ device, you need a resistor.

Manual reference: You can use charge sensors to measure physical phenomenon such as acceleration, p. 54

How do I measure AC current with NI-DAQmx?

To measure AC current, insert a precisely calibrated, low-value resistor into the signal path and measure the voltage drop across the resistor. Tips on Measuring AC Current Measuring current is an example of an analog input measurement.

Manual reference: Measuring current is an example of an analog input measurement. Refer to Analog; You can use charge sensors to measure physical phenomenon such as acceleration, pp. 57, 54

How do I measure temperature with NI-DAQmx?

The following flowchart depicts the main steps required in an NI-DAQmx application to measure temperature with a thermocouple. Measuring temperature is an example of analog input measurement. Measuring Temperature with a Thermocouple Programming

Manual reference: Measuring temperature is an example of analog input measurement. Refer to Analog, p. 111

How do I measure temperature with an RTD in NI-DAQmx?

Signal conditioning is generally required to measure temperature using an RTD. An RTD is a temperature sensing device with resistance that increases with temperature. Numerous types of RTDs exist, and they are typically defined by their material, their nominal resistance, and their temperature coefficient of resistance (TCR).

Manual reference: An RTD is a temperature sensing device with resistance that increases with, p. 631

How do I measure temperature with a thermistor in NI-DAQmx?

The following flowchart depicts the main steps required in an NI-DAQmx application to measure temperature with a thermistor. Measuring Temperature with a Thermistor Programming Alternatively, you can configure a task for measuring temperature using the DAQ Assistant.

Manual reference: Measuring Temperature with a Thermistor Programming; Measuring temperature is an example of analog input measurement. Refer to Analog, pp. 110, 111

How do I measure temperature with a thermocouple in NI-DAQmx?

The following flowchart depicts the main steps required in an NI-DAQmx application to measure temperature with a thermocouple. Measuring Temperature with a Thermocouple Programming Measuring temperature is an example of analog input measurement.

Manual reference: Measuring temperature is an example of analog input measurement. Refer to Analog, p. 111

How do I measure strain with NI-DAQmx?

To measure strain, you can use one or more strain gages in a Wheatstone bridge in one of several bridge configurations. The following flowchart depicts the main steps required in an NI-DAQmx application to measure strain. Alternatively, you can configure a task to measure strain with a strain

Manual reference: Measuring Strain, p. 104

How do I measure force with NI-DAQmx?

The following flowchart depicts the main steps required in an NI-DAQmx application to measure force with a piezoelectric force sensor. Measuring force is an example of analog input measurement. Measuring Force with a Piezoelectric Sensor Programming

Manual reference: Measuring Force with a Piezoelectric Sensor Programming, p. 64

How do I measure force with a piezoelectric sensor in NI-DAQmx?

The following flowchart depicts the main steps required in an NI-DAQmx application to measure force with a piezoelectric force sensor. Measuring Force with a Piezoelectric Sensor Programming Measuring force is an example of analog input measurement.

Manual reference: Measuring Force with a Piezoelectric Sensor Programming, p. 64

How do I measure pressure with NI-DAQmx?

The following flowchart depicts the main steps required in an NI-DAQmx application to measure pressure. Measuring pressure is an example of analog input measurement. Measuring Pressure Programming Flowchart

Manual reference: Measuring Pressure Programming Flowchart, p. 95

How do I measure sound pressure with NI-DAQmx?

The following flowchart depicts the main steps required in an NI-DAQmx application to measure sound pressure. Measuring sound pressure is an example of an analog input measurement. Measuring Sound Pressure Programming Flowchart

Manual reference: Measuring Sound Pressure Programming Flowchart, p. 103

How do I measure resistance with NI-DAQmx?

Use this workflow from the manual:

1. Use the 3-wire resistance method, as shown in the following figure, to measure resistance on resistors that have three lead wires.
2. resistance through the same set of leads and computes the resistance accordingly.

Manual reference: Errors in the 2-wire measurements are introduced by the lead resistance, RLead, when, p. 596

How do I measure calculated power with NI-DAQmx?

Use this workflow from the manual:

1. Devices that can measure calculated power use a combination of voltage measurements and current measurements.
2. Use Ohm's Law to measure voltage dropped across the load and the resistor while also converting to power.

Manual reference: Use Ohm's Law to measure voltage dropped across the load and the resistor while also; Edge counting is an example of a counter measurement. Refer to Counter, pp. 51, 50

How do I configure finite analog input?

You can configure a task for finite analog input using the DAQ Assistant. Finite Analog Input Programming Flowchart One way to acquire multiple samples for one or more channels is to acquire single samples in a repetitive manner.

Manual reference: Finite Analog Input Programming Flowchart, p. 69

How do I configure continuous analog input?

Instead, you can configure a task for continuous analog input using the DAQ Assistant. Continuous Analog Input Programming Flowchart If you want to view, process, or log a subset of the samples as they are being acquired, you need to continually acquire samples.

Manual reference: Continuous Analog Input Programming Flowchart, p. 70

How do I configure finite analog output?

Continuous Analog Output Programming Flowchart generate a finite number of voltage samples in a buffered generation.

Manual reference: Continuous Analog Output Programming Flowchart, p. 73

How do I configure continuous analog output?

Continuous Analog Output Programming Flowchart The following flowchart depicts the main steps required in an NI-DAQmx application to continuously generate voltage samples. If you prefer, you can configure this task using the DAQ Assistant.

Manual reference: Continuous Analog Output Programming Flowchart; Analog Output Timing Considerations for C Series Devices, pp. 73, 471

What is regeneration in NI-DAQmx?

This type of regeneration is sometimes called PC memory or user buffer regeneration.

Manual reference: When the Use Only Onboard Memory attribute/property is false, NI-DAQmx; USB Bulk, pp. 200, 199

How do I measure digital values with NI-DAQmx?

The following flowchart depicts the main steps required in an NI-DAQmx application to measure digital values. Measuring and generating digital values are used in a number of applications, including controlling relays and monitoring alarm states. Generally, measuring and generating digital values is used in laboratory testing, production testing, and industrial process monitoring and control.

Manual reference: This section covers software-timed digital input/output operations—or uns trobed, p. 59

How do I measure a digital value with NI-DAQmx?

The following flowchart depicts the main steps required in an NI-DAQmx application to measure digital values. Measuring and generating digital values are used in a number of applications, including controlling relays and monitoring alarm states. Generally, measuring and generating digital values is used in laboratory testing, production testing, and industrial process monitoring and control.

Manual reference: This section covers software-timed digital input/output operations—or uns trobed, p. 59

How do I configure finite digital input?

Finite Digital Input Programming Flowchart One way to acquire multiple samples for one or more channels is to acquire single samples in a repetitive manner. You can configure a task for measuring digital values using the DAQ Assistant.

Manual reference: Finite Digital Input Programming Flowchart, p. 79

How do I configure continuous digital input?

Continuous Digital Input Programming Flowchart If you want to view, process, or log a subset of the samples as they are being acquired, you need to continually acquire samples. Single Sample Digital Input Programming Flowchart

Manual reference: Continuous Digital Input Programming Flowchart, p. 80

How do I configure single-sample digital output?

Continuous Digital Output Programming Flowchart The following flowchart depicts the main steps required in an NI-DAQmx application to continuously generate digital values. If you prefer, you can configure a task for generating digital values using the DAQ Assistant.

Manual reference: Continuous Digital Output Programming Flowchart, p. 83

How do I configure continuous digital output?

Continuous Digital Output Programming Flowchart The following flowchart depicts the main steps required in an NI-DAQmx application to continuously generate digital values. If you prefer, you can configure a task for generating digital values using the DAQ Assistant.

Manual reference: Continuous Digital Output Programming Flowchart, p. 83

What is the difference between digital lines and digital ports?

Digital lines and ports are important parts of a digital input/output system. Port—A port is a c ollection of digital lines. Digital Lines, Ports, and Port Width

Manual reference: Dev1/port0:1, p. 126

What is digital pattern triggering in NI-DAQmx?

Digital Pattern Triggering For digital pattern triggering, you configure the device to detect a specific digital pattern on specific physical channels.

Manual reference: TTL Signal, p. 163

How do I measure digital frequency with NI-DAQmx?

The following flowchart depicts the main steps required in an NI-DAQmx application to measure digital frequency or period. Digital frequency and period are examples of counter measurements. Measuring Digital Frequency and Period Programming

Manual reference: Digital frequency and period are examples of counter measurements. Refer to Counter, p. 66

How do I measure analog frequency with NI-DAQmx?

Use this workflow from the manual:

1. Alternatively, you can configure a task for measuring analog frequency using the DAQ Assistant.
2. For example, you need to collect at least 15 samples, or points, if you use a sampling rate of 500 S/s to measure the frequency of a 100 Hz signal.
3. For devices that cannot measure frequency directly, you need to use software algorithms, such as the Fast Fourier Transform (FFT), to convert voltage to frequency.
4. In practice, you should use sampling rates of 5 to 10 times the expected frequencies to improve accuracy of measurements.
5. Regardless of whether you use existing VIs or functions or create your own, you need to sample at least twice as fast as the highest frequency component in the signal you are acquiring.

Manual reference: Measuring Analog Frequency Programming Flowchart; For devices that cannot measure frequency directly, you need to use software, pp. 41, 39

How do I measure period with NI-DAQmx?

Digital frequency and period are examples of counter measurements. The following flowchart demonstrates the main steps required in an NI-DAQmx application to measure semi-period and pulse width. Measuring Semi-Period, Two-Edge Separation, and Pulse

Manual reference: Digital frequency and period are examples of counter measurements. Refer to Counter, p. 93

How do I measure semi-period with NI-DAQmx?

The following flowchart demonstrates the main steps required in an NI-DAQmx application to measure semi-period and pulse width. Measuring Semi-Period, Two-Edge Separation, and Pulse Alternatively, you can configure a task for measuring semi-period and pulse width using the DAQ Assistant.

Manual reference: Digital frequency and period are examples of counter measurements. Refer to Counter, p. 93

How do I measure pulse width with NI-DAQmx?

Period, semi-period, two-edge separation, and pulse width is an example of a counter measurement. Pressure is a measure of force per unit area. You can use bridge-based sensors to measure pressure.

Manual reference: Period, semi-period, two-edge separation, and pulse width is an example of a counter; Period measurements measure the time between consecutive rising or falling edges of, pp. 94, 91

How do I measure two-edge separation with NI-DAQmx?

Period, semi-period, two-edge separation, and pulse width is an example of a counter measurement. Pressure is a measure of force per unit area. You can use bridge-based sensors to measure pressure.

Manual reference: Period, semi-period, two-edge separation, and pulse width is an example of a counter; Digital frequency and period are examples of counter measurements. Refer to Counter, pp. 94, 93

How do I measure duty cycle with NI-DAQmx?

Use this workflow from the manual:

1. You can use the counters on your measurement device to measure duty cycle.
2. Use the following equation to calculate the duty cycle of a pulse:

Manual reference: Measuring Duty Cycle, p. 60

How do I generate a pulse with NI-DAQmx?

Before you generate a pulse, you need to determine if you want to output the pulse or pulse train in terms of frequency, time, or number of ticks of the counter timebase. The following flowchart depicts the main steps required in an NI-DAQmx application to generate a pulse. If you prefer, you can configure a task to generate a pulse using the

Manual reference: Before you generate a pulse, you need to determine if you want to output the pulse or, p. 98

How do I generate a finite pulse train with NI-DAQmx?

Generating a Finite Pulse Train Programming Flowchart The following flowchart depicts the main steps required in an NI-DAQmx application for generating a finite pulse train. Alternatively, you can configure a task for generating the pulse train using the DAQ Assistant.

Manual reference: Generating a Finite Pulse Train Programming Flowchart; Before you generate a pulse, you need to determine if you want to output the pulse or, pp. 99, 98

How do I generate a continuous pulse train with NI-DAQmx?

Use this workflow from the manual:

1. If you prefer, you can configure a task to generate a pulse using the
2. Alternatively, you can configure a task for generating the pulse train using the DAQ Assistant.
3. When you configure a pulse generation, the output appears at the counter output terminal.

Manual reference: Generating a Continuous Pulse Train Programming Flowchart; Before you generate a pulse, you need to determine if you want to output the pulse or, pp. 100, 98

What are paired counters in NI-DAQmx?

Paired counters are generally numbered sequentially. NI-DAQmx automatically takes care of making the internal routes necessary to perform the measurement across paired counters.

Manual reference: Paired Counters, p. 209

What is the two-counter measurement method?

Large-Range Two-Counter Measurement Method To perform measurements using this method in NI-DAQmx, a paired counter is used to

Manual reference: To determine if you should use the high-frequency measurement method, refer to the, p. 210

What is the high-frequency two-counter measurement method?

Large-Range Two-Counter Measurement Method Use the lareg-range two-counter method to measure signals with large ranges or high frequencies.

Manual reference: To determine if you should use the high-frequency measurement method, refer to the, p. 210

What is the large-range two-counter measurement method?

Large-Range Two-Counter Measurement Method Use the lareg-range two-counter method to measure signals with large ranges or high frequencies.

Manual reference: To determine if you should use the high-frequency measurement method, refer to the, p. 210

What is quantization error in counter measurements?

For example, if the counter timebase rate is 20 MHz, and the frequency of the input signal is 5 MHz, the measured value can be 3, 4, or 5 due to quantization error. Quantization Error with One Counter Time Measurements

Manual reference: Quantization Error, p. 212

What is the dynamic averaging method?

As a result, the dynamic averaging method balances measurement accuracy vs. During an acquisition, the dynamic averaging method will average between 1 period and divisor periods of the input signal to determine the input signal's frequency.

Manual reference: During an acquisition, the dynamic averaging method will average between 1 period, p. 219

What are counter parts in NI-DAQmx?

Counter Parts The main parts of a counter include the following:

Manual reference: Counter Output Event as the signal name. After you route the internal output of a, p. 222

How do I configure triggers for pulse generation?

Use this workflow from the manual:

1. You can use a pulse or pulse train as a clock signal, a gate, or a trigger for a measurement or a pulse generation.
2. You can use a single pulse of known duration to determine an unknown signal frequency or to trigger an analog acquisition.
3. You can use a pulse train of known frequency to determine an unknown pulse width.

Manual reference: Generating Pulses, p. 97

How do I set pulse train polarity and initial delay state?

Setting Pulse Train Polarity and the Initial Delay State The idle state, which controls the pulse train polarity, is applied to the signal when a task transitions to the Committed state (which happens automatically when the task starts). The idle state polarity also determines the state of the initial delay.

Manual reference: Initial Delay, p. 228

What is counter frequency coercion?

Counter Frequency Coercion The frequency of the counter output must be evenly divisible into the frequency of its timebase.

Manual reference: Initial, p. 229

How do I measure angular displacement with NI-DAQmx?

One type of sensor used to measure angular displacement is a rotary variable differential transformer (RVDT). Another type of sensor used to measure angular displacement is a resolver, which is a rotating transformer that can measure An angular displacement sensor is a device whose output signal represents the rotation of the shaft; it cannot measure the physical displacement of the whole shaft.

Manual reference: Input Programming Flowcharts for additional flowcharts that can help you create an, p. 42

How do I measure velocity with NI-DAQmx?

You also can measure velocity with two-pulse encoders, but you need to use a sample clock with a fixed frequency. To measure velocity, use the following formula: The linear variable differential transformer (LVDT) is a sensor that measures linear displacement.

Manual reference: GPS timestamp is an example of a counter measurement. Refer to Counter, p. 87

How do I measure velocity with an IEPE velocity transducer?

Measuring Velocity with an IEPE Velocity Transducer A velocity transducer is an IEPE sensor that converts velocity to voltage. Velocity transducers are typically used to measure vibration.

Manual reference: Measuring temperature is an example of analog input measurement. Refer to Analog, p. 112

How do I measure linear velocity with an encoder?

Linear velocity can be measured with X1, X2, and X4 quadrature encoders. Measuring Linear Velocity (Encoder) On devices that support it, you can use the counters to perform velocity measurements with encoders.

Manual reference: The counter measures the velocity of the encoder using the A and B signals, which are, p. 114

How do I measure proximity with NI-DAQmx?

An eddy current proximity probe is a transducer that uses changes in voltage to measure proximity. The following flowchart depicts the main steps required in an NI-DAQmx application to measure proximity using an eddy current proximity probe. Eddy current proximity probes use a high-frequency radio signal to convert voltage to a proximity measurement.

Manual reference: Measuring Proximity, p. 96

How do I measure a GPS timestamp with NI-DAQmx?

GPS timestamp is an example of a counter measurement. The linear variable differential transformer (LVDT) is a sensor that measures linear displacement. You also can measure velocity with two-pulse encoders, but you need to use a sample clock with a fixed frequency.

Manual reference: GPS timestamp is an example of a counter measurement. Refer to Counter, p. 87

What is an advance trigger?

An Advance Trigger causes a switch device to execute the next entry in its instruction

Manual reference: Triggering; Pretrigger, pp. 157, 159

What is an arm start trigger?

The Arm Start Trigger is used to arm the task and waits for a single trigger event before allowing the Start Trigger to activate.

Manual reference: Pretrigger, p. 159

What is an expiration trigger?

Expiration Trigger An Expiration Trigger expires a watchdog task.

Manual reference: Expiration Trigger, p. 158

What is a handshake trigger?

A Handshake Trigger is a control signal from a peripheral device.

Manual reference: Expiration Trigger, p. 158

What is a pause trigger?

Pause Trigger is deasserted. Pause Trigger is asserted, not at the end of a pulse.

Manual reference: Pause Triggers can affect your measurement., p. 355

What is a reference trigger?

Reference Trigger A Reference Trigger establishes the reference point in a set of input samples.

Manual reference: Expiration Trigger, p. 158

What is a start trigger?

A Start Trigger begins an acquisition or generation. The Arm Start Trigger is used to arm the task and waits for a single trigger event before allowing the Start Trigger to activate.

Manual reference: Pretrigger, p. 159

What is analog edge triggering?

Analog Edge Triggering For analog edge triggering, you configure the measurement device to look for a certain signal level and slope (either rising or falling).

Manual reference: Pretrigger, p. 159

What is analog level triggering?

Analog Level Triggering An analog level trigger is similar to an analog edge trigger.

Manual reference: Hysteresis+Level, p. 161

What is analog window triggering?

Analog Window Triggering A window trigger occurs when an analog signal either passes into (enters) or passes out of (leaves) a window defined by two voltage levels.

Manual reference: Analog Window Triggering, p. 162

What is digital edge triggering?

Digital Edge Triggering A digital trigger is usually a TTL signal with two discrete levels: a high and a low level.

Manual reference: Analog Window Triggering, p. 162

What is digital level triggering?

Digital level triggering starts, stops, or pauses an acquisition or measurement based on the value read on a digital line.

Manual reference: TTL Signal, p. 163

What is digital pattern triggering?

Digital Pattern Triggering For digital pattern triggering, you configure the device to detect a specific digital pattern on specific physical channels.

Manual reference: TTL Signal, p. 163

What are software triggers?

Software Triggers Software triggering starts, stops, or pauses an acquisition or measurement or advances a scan list based on a software trigger command being sent.

Manual reference: Requested, p. 164

How do I configure triggered acquisition in NI-DAQmx?

Triggered Acquisition Programming Flowchart The following flowchart depicts the main steps you follow for adding triggering to an acquisition. If you prefer, you can configure triggering with the DAQ Assistant.

Manual reference: Triggered Acquisition Programming Flowchart; LabVIEW require properties. ANSI C and LabWindows/CVI employ the Get and Set, pp. 84, 68

How do analog trigger sources vary by device type?

Valid Analog Trigger Sources for DSA Devices The analog trigger source must be a channel included in your physical channel list. 0 is not a valid analog trigger source.

Manual reference: Valid Analog Trigger Sources for DSA Devices, p. 284

What is synchronization in NI-DAQmx?

Sample Clock synchronization allows you to synchronize tasks on multiple devices at the same rate. Reference Clock synchronization ensures that all synchronized devices maintain phase

Manual reference: Sample Clock Synchronization, p. 170

What is the difference between lockstep and handshaked synchronization?

Handshaked synchronization (or stimulus/response) is two or more devices acting in sequence. In handshaked synchronization, triggers and events are typically shared. Types of Synchronization, Lockstep and Handshaked

Manual reference: Selecting a terminal as the source of a clock or a trigger constructs a route. On PCI, p. 166

What are master and slave devices in NI-DAQmx synchronization?

Master and Slave Devices However, the shared Start Trigger must travel from the master device to the slave devices, resulting in skew.

Manual reference: Reference Clock synchronization minimizes or eliminates skew in the clocks. However,, p. 172

What sources of synchronization error does NI-DAQmx describe?

You can describe timing errors in several different ways. There are several sources of error when synchronizing measurements:

Manual reference: Sources of Error, p. 168

What is jitter in NI-DAQmx synchronization?

Sample Clock synchronization allows you to synchronize tasks on multiple devices at the same rate. On multiplexed devices, Sample Clock synchronization results in jitter because, even though you synchronized the Sample Clock, the devices do not synchronize the AI Convert Clock.

Manual reference: Sample Clock Synchronization, p. 170

What is accuracy in NI-DAQmx synchronization?

Reference Clock synchronization allows you to synchronize timing for the synchronized devices, even if the devices operate at different rates or belong to different subsystems.

Manual reference: Reference Clock synchronization allows you to synchronize timing for the, p. 171

What is skew in NI-DAQmx synchronization?

Sample Clock synchronization allows you to synchronize tasks on multiple devices at the same rate.

Manual reference: Sample Clock Synchronization, p. 170

What is sample clock synchronization?

Sample Clock synchronization allows you to synchronize tasks on multiple devices at the same rate.

Manual reference: Sample Clock Synchronization, p. 170

What is reference clock synchronization?

Reference Clock synchronization allows you to synchronize timing for the synchronized devices, even if the devices operate at different rates or belong to different subsystems. For counter operations, Reference Clock synchronization ensures the following:

Manual reference: Reference Clock synchronization allows you to synchronize timing for the, p. 171

What is master timebase synchronization?

Master Timebase synchronization ensures the following: Master Timebase synchronization results in skew due to the time required for the clock to travel between devices.

Manual reference: Reference Clock synchronization minimizes or eliminates skew in the clocks. However,; When using Master Timebase synchronization, slave devices replace their onboard, pp. 172, 173

What is sample clock timebase synchronization?

Sample Clock Timebase synchronization allows you to synchronize devices at different rates.

Manual reference: Sample Clock Timebase Synchronization, p. 174

What is signal routing in NI-DAQmx?

The ways that NI-DAQmx handles timing, triggering, buffering, and signal routing are also central in the NI-DAQmx API. A physical channel is a terminal or pin at which you can measure or generate an analog or digital signal.

Manual reference: NI-DAQmx Key Concepts; E Series and S Series Valid Sources for the Analog Trigger, pp. 121, 285

What is the difference between single-device routing and multi-device routing?

Single-Device Routing Versus Multi-Device Routing A single-device route is a connection between two terminals on the same physical device. NI-DAQmx introduces multi-device routing.

Manual reference: Specifying a Route, p. 203

How do I create multi-device routes?

To create a multi-device route, the source and destination devices must share a trigger bus both physically and logically in MAX. Creating Multi-Device Routes You simply specify the source terminal and destination terminal.

Manual reference: Specifying a Route, p. 203

How do I register an RTSI cable in MAX?

Use this workflow from the manual:

1. For more information on how to register (or add) a RTSI cable in MAX, refer to Measurement & Automation Explorer Help for NI-DAQmx.
2. If you do not register your RTSI cable, NI-DAQmx fails to create a route.
3. You must use a RTSI cable to connect the devices, and you must identify the cable in MAX.
4. To create a multi-device route, the source and destination devices must share a trigger bus both physically and logically in MAX.

Manual reference: You must use a RTSI cable to connect the devices, and you must identify the cable; Specifying a Route, pp. 512, 513, 203

What is task-based routing?

Task-based routing is the most common form of routing.

Manual reference: Dynamically Selecting Trigger Bus Lines, p. 204

What is immediate routing?

Immediate routing is not associated with any task. Immediate Routing

Manual reference: Dynamically Selecting Trigger Bus Lines, p. 204

What is logical inversion of signals?

Logical Inversion of Signals If you route a signal to or from an external device, you might need to invert the polarity of the signal.

Manual reference: Logical Inversion of Signals, p. 205

How do routing and hardware sharing interact?

Routing and Hardware Sharing Device Resetting and Interactions with Routing

Manual reference: Logical Inversion of Signals, p. 205

What are lazy line transitions?

Refer to Lazy Line Transitions for more information. Lazy Line Transitions

Manual reference: Dynamically Selecting Trigger Bus Lines, p. 204

How does device resetting interact with routing?

Refer to Device Resetting and Interactions with Routing for more information. There are other ways to destroy routes such as resetting the device. Multi-device routing allows you to dynamically select trigger lines at run time.

Manual reference: Dynamically Selecting Trigger Bus Lines, p. 204

How do I view device routing in MAX?

Device Routing in MAX To find the device routing table for your device, launch MAX and select Devices and Note MAX does not display the device routing table for SCXI chassis, SCC connector blocks, or RTSI cable devices.

Manual reference: Device Routing in MAX, p. 208

How do I read data in NI-DAQmx?

Use this workflow from the manual:

1. You can also read data while logging to disk.
2. If logging and reading data, ensure the number of samples per channel to read is evenly divisible by the sector size of the hard disk.
3. When this attribute/property is false, you can also set the Data Transfer Request
4. Condition attribute/property to specify when to transfer data from the host buffer to the device.
5. Thus, if you write new data to the device after starting the task, that new data is generated and regenerated until you write more new data.
6. When the Use Only Onboard Memory attribute/property is false, NI-DAQmx continuously transfers data from the host memory buffer to the device even though this data is not changing.

Manual reference: When the Use Only Onboard Memory attribute/property is false, NI-DAQmx, p. 200

How do I write data in NI-DAQmx?

Selecting Read and Write Data Format and Organization The read and write VIs have two major selection criteria: data format and data organization. Data Transfer Mechanisms

Manual reference: Reading and Writing Data; There are often multiple legal data organizations to choose from. The main tradeoff to, pp. 182, 186

How do I select read and write data formats?

Selecting Read and Write Data Format and Organization The read and write VIs have two major selection criteria: data format and data organization. This section covers buffering and selecting data formats and organization.

Manual reference: Reading and Writing Data; Data Formats in NI-DAQmx, pp. 182, 183

What is data organization in NI-DAQmx?

There are often multiple legal data organizations to choose from. The main tradeoff to consider for data organization is difficulty in manipulation of the data.

Manual reference: There are often multiple legal data organizations to choose from. The main tradeoff to, p. 186

What is interleaving in NI-DAQmx?

Interleaving Interleaved samples prioritize samples before channels, such that the array lists the first sample from every channel in the task, then the second sample from every channel, up to the last sample from every channel.

Manual reference: Interleaving; Unscaled Data, pp. 188, 190

What is raw data in NI-DAQmx?

The raw data format is defined by the native data format of the device. Data format deals with the type of the data that is read or written.

Manual reference: Data Formats in NI-DAQmx; The port format is the most efficient in terms of space, as it requires only a bit of, pp. 183, 185

What is unscaled data in NI-DAQmx?

Unscaled data is in the native format of the device, read directly from the device or buffer without scaling.

Manual reference: Unscaled Data, p. 190

What are waveform timing limitations?

Waveform Timing Limitations The limitation on t0 is that NI-DAQmx calculates the starting time for the task when data is read the first time.

Manual reference: Unscaled Data, p. 190

What are NI-DAQmx data transfer mechanisms?

Data Transfer Mechanisms This section covers buffering and selecting data formats and organization.

Manual reference: Reading and Writing Data, p. 182

What is TDMS logging in NI-DAQmx?

Technical Data Management Streaming (TDMS) is a binary file format that allows for high-speed data logging.

Manual reference: When the Use Only Onboard Memory attribute/property is false, NI-DAQmx, p. 200

How do I log data across multiple files?

You can split TDMS logs across multiple files by using either the DAQmx Start New File function/VI or the Logging.SampsPerFile attribute/property. Logging Across Multiple Files If the logging mode is set to Log, data is written to disk on multiples of the Logging.FileWriteSize attribute/property.

Manual reference: Logging Across Multiple Files, p. 201

What is on-demand logging?

On-Demand Logging For on-demand logging, NI-DAQmx creates a Time channel in the TDMS file that contains timestamp data.

Manual reference: To change a file immediately, you can also use the DAQmx Start New File function/VI, p. 202

What is a terminal in NI-DAQmx?

A terminal, on the other hand, is a named location where a signal is either generated (output or produced) or acquired (input or consumed).

Manual reference: Signal Versus Terminal, p. 230

What is the difference between a signal and a terminal?

A terminal, on the other hand, is a named location where a signal is either generated (output or produced) or acquired (input or consumed). When a terminal shares a name with a signal, it is not always clear which is being referred to— the terminal or the signal. Within most devices, there is a terminal such that the signal at that terminal is always used as the sample clock.

Manual reference: Signal Versus Terminal, p. 230

What are terminal names in NI-DAQmx?

When a terminal shares a name with a signal, it is not always clear which is being referred to— the terminal or the signal. For analog output tasks, this terminal is named the ao/

Manual reference: Signal Versus Terminal, p. 230

What are analog input accessory terminal names?

Analog Input Accessory Terminal Names The following table lists the revised names for analog input terminal names.

Manual reference: Analog Input Accessory Terminal Names, p. 237

What are analog output accessory terminal names?

Analog Output Accessory Terminal Names The following table lists the revised names for analog output terminal names.

Manual reference: Analog Output Accessory Terminal Names, p. 238

What are counter accessory terminal names?

Counter Accessory Terminal Names Analog Output Accessory Terminal Names

Manual reference: Analog Output Accessory Terminal Names, p. 238

What are digital accessory terminal names?

Digital Accessory Terminal Names The following table lists the revised names for digital terminal names.

Manual reference: Digital Accessory Terminal Names, p. 239

What is the syntax for terminal names?

The syntax for terminal names is a unique identifier that refers to a physical terminal in your system. Syntax for Terminal Names

Manual reference: Digital Accessory Terminal Names, p. 239

How do I connect counter signals for C Series and TestScale modules?

C Series and TestScale Module Signal Connections for Counters (Large Range with Two Counters) PFI 0 PFI 4 PFI 3 PFI 7

Manual reference: C Series and TestScale Module Signal Connections for Counters, p. 309

How do I connect counter signals for X Series devices?

Use this workflow from the manual:

1. Connect the positive output of your reference voltage source to ACH0+.
2. Connect the negative output of your reference voltage source to ACH0-. Device Calibration Signal Connections for M Series and NI 6010
3. Disconnect any external connections or circuitry to your device.
4. Connect the positive output of your reference voltage source to physical channel ai0.
5. Connect the negative output of your reference voltage source to physical channel ai8.
6. If your reference voltage source and your computer are floating with respect to each other, connect the negative output of your reference voltage source to the AI GND terminal as well as to physical channel ai8.
7. Connect physical channel ao0 to physical channel ai0.
8. If your reference voltage source and your computer are floating with respect to each other, connect the AI SENSE terminal to the AI GND terminal as well as to the negative output of your reference voltage source.

Manual reference: Device Calibration Signal Connections for M Series and NI 6010; Device Calibration Signal Connections for S Series Devices, pp. 302, 301

How do I connect counter signals for M Series devices?

Use this workflow from the manual:

1. Connect the positive output of your reference voltage source to ACH0+.
2. Connect the negative output of your reference voltage source to ACH0-. Device Calibration Signal Connections for M Series and NI 6010
3. Disconnect any external connections or circuitry to your device.
4. Connect the positive output of your reference voltage source to physical channel ai0.
5. Connect the negative output of your reference voltage source to physical channel ai8.
6. If your reference voltage source and your computer are floating with respect to each other, connect the negative output of your reference voltage source to the AI GND terminal as well as to physical channel ai8.
7. Connect physical channel ao0 to physical channel ai0.
8. If your reference voltage source and your computer are floating with respect to each other, connect the AI SENSE terminal to the AI GND terminal as well as to the negative output of your reference voltage source.

Manual reference: Device Calibration Signal Connections for M Series and NI 6010; Device Calibration Signal Connections for S Series Devices, pp. 302, 301

How do I connect counter signals for NI ELVIS II devices?

Use this workflow from the manual:

1. Connect the positive output of your reference voltage source to ACH0+.
2. Connect the negative output of your reference voltage source to ACH0-. Device Calibration Signal Connections for M Series and NI 6010
3. Disconnect any external connections or circuitry to your device.
4. Connect the positive output of your reference voltage source to physical channel ai0.
5. Connect the negative output of your reference voltage source to physical channel ai8.
6. If your reference voltage source and your computer are floating with respect to each other, connect the negative output of your reference voltage source to the AI GND terminal as well as to physical channel ai8.

Manual reference: Device Calibration Signal Connections for M Series and NI 6010, p. 302

What is calibration in NI-DAQmx?

Device calibration consists of verifying the measurement accuracy of a device and adjusting for any measurement error.

Manual reference: Device Calibration Considerations, p. 289

What is device calibration?

Device calibration consists of verifying the measurement accuracy of a device and adjusting for any measurement error.

Manual reference: Device Calibration Considerations, p. 289

What is virtual channel calibration support?

Virtual Channel Calibration Support The following devices do not support NI-DAQmx virtual channel calibration:

Manual reference: Virtual Channel Calibration Support, p. 291

What are device groups in NI-DAQmx?

Device Groups in NI-DAQmx Refer to the following list to see how devices are grouped in NI-DAQmx.

Manual reference: NI-DAQmx Device Considerations, p. 275

What is control in NI-DAQmx?

There are many data processing algorithms to consider when creating a control application.

Manual reference: Timing Control Loops, p. 262

What are NI-DAQmx single-point real-time applications?

Timing control loops, synchronizing analog input and output, using control algorithms, single-point real-time applications, and setting priorities for control applications in LabVIEW are described.

Manual reference: Control in NI-DAQmx; Sample Application—Har dware-Timed Counter Tasks, pp. 243, 253

What is hardware-timed input with software-timed output?

An example of this kind of application is an analog control loop that reads samples from a specific number of multiplexed analog input channels, processes the data using a control algorithm (such as PID), and writes the new control values to the analog output channels using a software-timed task. Input samples are hardware-timed.

Manual reference: Hardware-Timed Input, Software-Timed Output, p. 250

What are hardware-timed counter tasks?

Hardware-Timed Counter Tasks Requirement—U se hardware-timed counter input operations to drive a control loop.

Manual reference: Hardware-Timed Counter Tasks, p. 252

How do I time control loops in NI-DAQmx?

You can time control loops using software timing or hardware timing. Timing Control Loops Control Loops in the Common Applications section uses hardware timing.

Manual reference: Timing Control Loops, p. 262

How do I use control algorithms in NI-DAQmx?

Timing control loops, synchronizing analog input and output, using control algorithms, single-point real-time applications, and setting priorities for control applications in LabVIEW are described. Setting Priorities for Control Applications in LabVIEW

Manual reference: Control in NI-DAQmx, p. 243

What are I/O cycles in NI-DAQmx?

The input and output operations along with any processing performed during a single sample clock period are called I/O cycles.

Manual reference: I/O Cycles; Digital Logic States, pp. 264, 590

What is the DAQmx I/O Server?

I/O Server for distributed applications. DAQmx I/O Server and Virtual Channels

Manual reference: Digital data is always returned as if each eight-bit port were a binary counter for both; You must deploy your tasks and channels using the MAX Export Wizard if you create, pp. 266, 268

How do DAQmx I/O Server and virtual channels work together?

Use this workflow from the manual:

1. Use Dev1/ai0 as the physical channel on the device to which the thermocouple signal is connected.
2. Specify myThermocoupleChannel as the name to assign to your virtual channel.
3. Select the appropriate values for the thermocouple type and range inputs. NI-DAQmx applies these attributes to the virtual channel.

Manual reference: DAQmx applies these attributes to the virtual channel., p. 123

NI-DAQmx vs Traditional NI-DAQ: what is the difference?

Call the Traditional NI-DAQ (Legacy) Device Reset function/VI. The device must be calibrated using the Traditional NI-DAQ (Legacy) driver. Right-click the Traditional NI-DAQ (Legacy) Devices folder in MAX and select Reset

Manual reference: NI 6614 Calibration, p. 296

DAQ Assistant vs NI-DAQmx API: what is the difference?

Choosing Whether to Use the API or the DAQ Assistant Creating Channels and Tasks with the DAQ Assistant Use the DAQmx Task Name control to open the DAQ Assistant.

Manual reference: Creating Channels and Tasks with the DAQ Assistant, p. 142

Hardware timing vs software timing in NI-DAQmx: what is the difference?

You can use software timing or hardware timing to control when a signal is generated. Timing, Hardware Versus Software With hardware timing, a digital signal, such as a clock on your device, controls the rate of generation.

Manual reference: Timing, Hardware Versus Software, p. 144

Physical channels vs virtual channels in NI-DAQmx: what is the difference?

This constraint applies to virtual channels as well as physical channels. The following example illustrates the difference between physical and virtual channels and demonstrates how to create virtual channels with the API. With this function/VI, you choose the name to assign for the virtual channel, which is used in the rest of the NI DAQmx software framework to refer to the physical channel.

Manual reference: This constraint applies to virtual channels as well as physical channels. For example, if; DAQmx software framework to refer to the physical channel., pp. 497, 122

Local virtual channels vs global virtual channels in NI-DAQmx: what is the difference?

These channels can be either global virtual channels or local virtual channels. Types of Virtual Channels You have now created a virtual channel.

Manual reference: DAQmx applies these attributes to the virtual channel., p. 123

Digital lines vs digital ports in NI-DAQmx: what is the difference?

These bidirectional digital lines allow you to Port NI-DAQmx Physical Channel Name (Lines) NI-DAQmx Physical Channel Name To configure a 16-bit port, use channel names that refer to all the lines in multiple consecutive ports:

Manual reference: Port NI-DAQmx Physical Channel Name (Lines) NI-DAQmx Physical Channel Name, p. 395

Start trigger vs reference trigger in NI-DAQmx: what is the difference?

Program all devices to use the same signal as their Digital Edge Start Trigger. On some devices using Reference This results in skew in the trigger signal.

Manual reference: Program all devices to use the same signal as their Digital Edge Start Trigger. This is, p. 176

Sample clock vs reference clock in NI-DAQmx: what is the difference?

Sample Clock Synchronization Sample Clock synchronization allows you to synchronize tasks on multiple devices at the same rate. When using Sample Clock synchronization, slave devices replace the Sample Clock for a given subsystem with the Sample Clock from another device.

Manual reference: Sample Clock Synchronization, p. 170

Raw data vs unscaled data in NI-DAQmx: what is the difference?

Unscaled Data Unscaled data is in the native format of the device, read directly from the device or buffer without scaling. The limitation on t0 is that NI-DAQmx calculates the starting time for the task when data is read the first time.

Manual reference: Unscaled Data, p. 190