NI-DAQmx Simulated Devices

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NI-DAQmx Simulated Devices

Publish Date: Dec 18, 2013

Table of Contents

Overview

How to Create an NI-DAQmx Simulated Device

How to Use an NI-DAQmx Simulated Device

Considerations for Using NI-DAQmx Simulated Devices

Want More NI-DAQmx Information?

The National Instruments Getting Started with NI-DAQmx Series is aimed at helping you learn NI-DAQmx programming fundamentals. Through

video and text tutorials, this series will take you from verifying your device's operation in Measurement & Automation Explorer (MAX) to

programming data acquisition applications using LabVIEW. It is intended for both the beginner who wants to learn how to use the DAQ Assistant, as

well as the experienced user who wishes to take advantage of advanced NI-DAQmx functionality.

1. Overview

NI-DAQmx not only provides DAQ system developers a high-performance driver, it also includes many measurement services designed to increase productivity. One of the newest and most

exciting measurement services added to NI-DAQmx is NI-DAQmx simulated devices. A simulated NI-DAQmx device is a replica of a device created using the NI-DAQmx Simulated Device option

in the Create New menu of MAX for the purpose of operating a function or program without hardware. An NI-DAQmx simulated device behaves similarly to a real device. Its driver is loaded, and

programs using it are fully verified.

This tutorial explains the basics of NI-DAQmx simulated devices, including how to create them, how to use them, as well as some considerations when using NI-DAQmx simulated devices.

Follow this tutorial using an installed copy of NI-DAQmx 7.4 or later and National Instruments application development software LabVIEW 7.x or later or LabVIEW SignalExpress Lite. If you do not

own National Instruments LabVIEW 7.x or higher, you can download SignalExpress Lite to help you complete this tutorial.

Most of this information is also available in the Measurement & Automation Explorer Help for NI-DAQmx (installed with the NI-DAQmx driver). Additional information about NI-DAQmx simulated

devices is in the NI-DAQmx Help (installed with the NI-DAQmx driver) and the DAQ Quick Start Guide (shipped with your DAQ device).

2. How to Create an NI-DAQmx Simulated Device

To create an NI-DAQmx simulated device, NI-DAQmx 7.4 or later must be installed.

1. Open Measurement & Automation Explorer (MAX). NI-DAQmx simulated devices are created within MAX. Unless you unchecked the feature during installation, MAX was installed when

NI-DAQmx was installed. If MAX is not installed, you must modify your installation of NI-DAQmx.

2. Right-click My System>>Devices and Interfaces and select Create New... In the subsequent dialog, select Simulated NI-DAQmx Device or Modular Instrument. The Create Simulated

NI-DAQmx Device window prompts you to select a device.

Figure 1. Create an NI-DAQmx simulated device in MAX.

3. Select the device you want to create as an NI-DAQmx simulated device. With this list, you can browse the hundreds of devices supported by NI-DAQmx. You can create an NI-DAQmx

simulated device of any NI-DAQmx-supported device, with the exception of the SCXI-1600 (NI-DAQmx 7.4 and later), USB-6008, USB-6009, USB-6501 and B Series devices (NI-DAQmx 7.5 and

later).

Note: The more drivers you have downloaded (NI-HSDIO, NI-SWITCH etc. the more options you will have to simulate)

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Figure 2. Choose from hundreds of NI-DAQmx supported devices.

4. Click OK in the Create Simulated NI-DAQmx Device window to close the window. The NI-DAQmx simulated device appears in MAX. The icon color of the NI-DAQmx simulated devices differs

from real devices. Real devices are green and chassis are grey while simulated devices and chassis are yellow.

Figure 3. NI-DAQmx simulated devices listed in MAX have yellow icons.

3. How to Use an NI-DAQmx Simulated Device

An NI-DAQmx simulated device works just as a real device. You can use NI-DAQmx simulated devices to create NI-DAQmx tasks either through the DAQ Assistant or the API. Because a real

device is no longer required to create an NI-DAQmx task, NI-DAQmx simulated devices allow developers to do the following:

Begin application development and logic without hardware

Develop application logic on a machine other than the target system

Evaluate acquisition functionality of National Instruments software without owning any hardware

This section of the tutorial describes how to create an NI-DAQmx task using the DAQ Assistant, then use the task to acquire simulated data in LabVIEW or LabVIEW SignalExpress.

1. Complete the previous section to create an NI-DAQmx simulated device in MAX.

2. Create an NI-DAQmx task in the DAQ Assistant.

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a. Right-click My System>>Data Neighborhood>>NI-DAQmx Tasks and select Create New NI-DAQmx Task. A window prompts you to select the measurement type.

Figure 4. Step 1 of the DAQ Assistant: Select a measurement type

b. Select Acquire Signals»Analog Input»Voltage as the measurement type for this task. A window prompts you to select the physical channels.

c. Select one or more channels from the NI-DAQmx simulated device. Both real and NI-DAQmx simulated devices are available for creating NI-DAQmx tasks, and the DAQ Assistant makes no

distinction

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