Summary: Choosing the right hardware and software is very important when setting up or upgrading an automatic controls lab. National Instruments LabVIEW can be used with a variety of hardware options for creating a real-time control system. Three control system hardware options are outlined for controlling plants, such as the ECP mechanical plants.
Choosing Lab Equipment
Software
National Instruments Applications and Toolkits
- LabVIEW 7.1, 8.0, or 8.2 Full Development System
- LabVIEW Real Time ETS or RTX (more detail under Choosing Lab Hardware)
- LabVIEW Control Design Toolkit
- LabVIEW Simulation Module
- LabVIEW FPGA
National Instruments Drivers:
- LabVIEW Device Driver CDs
- NI-RIO Driver CD
Venturecom Applications
- Real Time eXtention for Windows (RTX) (Optional)
Choosing Lab Hardware
The lab currently uses the hardware laid out as option one (1) below, LabVIEW Real-Time Module for ETS with PXI hardware. However, there are several hardware combinations that can be used for implementation of a Real-Time system to control ETS plants using LabVIEW. These options each have their own benefits. The options have been broken down by Real Time OS software support.
LabVIEW Real-Time Module for ETS
The LabVIEW Real-Time Module for ETS targets is for real-time devices that use a single dedicated kernel running embedded code. This option can be purchased from National Instruments for real-time PXI targets. It is also used for desktop PCs running as a dedicated real-time target.
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1. This option consists of a Windows PC communicating with a PXI real-time controller running LabVIEW Real-Time OS. The PXI-7831R intelligent data acquisition board is connected to the controller through the PXI bus. Control loops can be executed on both the Real-Time controller and on the intelligent data acquisition board. The ECP-RIO Adapter cable connects the 68pin VHDCI connector from the MIO connector on the PXI-7831R to the round encoder cable connected directly to the ECP plant. The banana plugs connect to the motor drive inputs on the front of the ECP Power supply. The ECP Amplifier is then connected to one of ECP's mechanical plants.
PXI provides a portable computing and acquisition solution that is rugged and rated for enviormnets where normal PC's can't go, making it ideal for both laboratory and research applications in many types of environments where determinism and reliability are crucial.
2. This option consists of a Windows PC communicating with a second PC running LabVIEW Real-Time OS (Real-Time OS PC Requirements). The PCI-7831R intelligent data acquisition board is connected to the PC through the PCI bus. Control loops can be executed on both the Real-Time OS running on the PCI and in the RIO intelligent data acquisition board. The ECP-RIO Adapter cable connects the 68pin VHDCI connector from the MIO connector on the PXI-7831R to the round encoder cable connected directly to the ECP plant. The banana plugs connect to the motor drive inputs on the front of the ECP Power supply. The ECP Amplifier is then connected to one of ECP's mechanical plants.
The Real-Time PC solution provides a lower cost real-time computing and acquisition platform that is ideal for laboratory and research applications, while still maintaining determinism and reliability.
The LabVIEW Real-Time Module for RTX
The LabVIEW Real-Time Module for RTX targets is used with desktop PCs running RTX, a real-time extension for Windows. This real-time operating system runs in parallel with Windows on the same processor, providing a single box solution for both user interface and deterministic operations. The OS can be purchased from National Instruments or from Venturecom directly. LabVIEW for RTX is a single PC solution for Real Time processing.
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3. This option consists of a Windows PC running Microsoft Windows, and Aredence's Realtime Extensions (RTX) (Will my PC work with RTX?) Windows and RTX run on the same computer, sharing the same CPU, but applications run in RTX maintain real-time execution. The PCI-7831R intelligent data acquisition board communicates with the PC through the standard PCI bus. Control loops can be executed on both in RTX and on the intelligent data acquisition board. The ECP-RIO Adapter cable connects the 68pin VHDCI connector from the MIO connector on the PXI-7831R to the round encoder cable connected directly to the ECP plant. The banana plugs connect to the motor drive inputs on the front of the ECP Power supply. The ECP Amplifier is then connected to one of ECP's mechanical plants.
The Real-Time RTX solution provides a single PC, low cost real-time computing and acquisition platform that is acceptable for laboratory applications.
Intellegent Data Acquision I/O Board :: PCI/PXI-7831R Reconfigurable Multifunction I/O Using the LabVIEW FPGA Module
Each solution uses the National Instruments PCI-7831R Reconfigurable FPGA. The FPGA is most useful because it offers 8 analog inputs, 8 analog outputs, and 96 digital I/O lines making it scalable for both teaching applications and research. The on board FPGA can be given a fixed personality for student use, or can be reprogrammed with the LabVIEW FPGA Module specifically for your needs. PID control loop rates up to 200,000 Hz. The 7831R also allows custom safety features to be implemented in the FPGA to protect students and equipment. Because these safety features are implemented in hardware, they are not dependent on the stability of the code running on the PC or real-time OS.
The following instructions and pin outs detail the wiring between the NI 7831R FPGA board to the ECP amplifier box. This cable is built and sold by National Instruments. You can download the cable detail and pin outs here: ECP Plant to NI RIO FPGA board (Download)
ECP Hardware
Please see ECP’s website for more information on ECP hardware options.
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