Real-Time System Components (RT Module)
A real-time system consists of software and hardware components. The software components include LabVIEW, the RT Engine, and the LabVIEW projects and VIs you create. The hardware components of a real-time system include a host computer and an RT target. The following sections describe the different components of a real-time system.
Host Computer
The host computer is a computer with LabVIEW and the LabVIEW Real-Time Module installed on which you develop the VIs for the real-time system. After developing the real-time system VIs, you can download and run the VIs on RT targets. The host computer can run VIs that communicate with VIs running on RT targets to provide a user interface.
LabVIEW
You develop VIs with LabVIEW on the host computer. The Real-Time Module extends the capabilities of LabVIEW with additional tools for creating, debugging, and deploying deterministic VIs.
LabVIEW Projects
Use LabVIEW projects to group LabVIEW files and non-LabVIEW files, create stand-alone real-time applications, and deploy or download VIs and other files to RT targets. When you save a project, LabVIEW creates a project file (.lvproj), which includes references to files in the project, configuration information, build information, and deployment information.
RT Engine
The RT Engine is a version of LabVIEW that runs on RT targets. The RT Engine runs the VIs you download to RT targets. The RT Engine provides deterministic real-time performance for the following reasons:
- The RT Engine runs on a real-time operating system (RTOS), which ensures that the LabVIEW execution system and other services adhere to real-time operation.
- The RT Engine runs on RT Series hardware. RT targets are designed to run only the VIs and device drivers necessary for RT applications, which prevents other applications from impeding the execution of RT VIs.
- RT targets do not use virtual memory, because virtual memory can cause unpredictable performance.
RT Target
An RT target refers to RT Series hardware that runs the RT Engine and VIs you create using LabVIEW. A networked RT Series device is a networked hardware platform with an embedded processor and a real-time operating system that runs the RT Engine and LabVIEW VIs. You can use a separate host computer to communicate with and control VIs on a networked RT Series device through an Ethernet connection. Some examples of networked RT Series devices include the following:
- NI RT Series PXI Controller—A networked device installed in an NI PXI chassis that communicates with NI PXI modules installed in the chassis. You can write VIs that use all the input/output (I/O) capabilities of the PXI modules, SCXI modules, and other signal conditioning devices installed in a PXI chassis. The RT Engine also supports features of the RT Series PXI controller. Refer to the LabVIEW Real-Time Support page on the National Instruments Web site for information about the features supported by the RT Engine on specific networked devices.
- NI CompactRIO Series—A reconfigurable control and acquisition system designed for applications that require high performance and reliability.
- NI RT Series [c]FP-2xxx—A networked device that runs the ETS RTOS.
- NI 1450 Series Compact Vision System—An easy-to-use, distributed, real-time imaging system that acquires, processes, and displays images from IEEE 1394 cameras.
- Desktop PCs as RT Targets—A desktop PC configured with RT Engine software. Refer to the Using Desktop PCs as RT Targets with the LabVIEW Real-Time Module document for information about desktop PC targets.
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Note The LabVIEW Help does not contain hardware-related information about specific networked devices. Refer to the appropriate device documentation for information about the device. |
USB Storage Devices
The Real-Time Module includes support for USB storage devices, such as thumb drives and external USB hard drives, for RT targets that have onboard USB hardware. Connect an external USB storage device to a USB port of an RT target and then access the device from VIs running on the RT target.
When you plug a USB thumb drive into the RT system, the thumb drive is automatically assigned a drive letter of U:. Each additional drive you add is automatically assigned the next available drive letter. For example, V:, W::, X:, and so on.
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Caution Disconnecting a USB drive during operation can cause data corruption. To maintain data integrity, close all files on the USB drive before disconnecting the drive. |