Real-Time Event-Based Sequencer Reference Example

The following attachment includes three components, the Real-Time Event-Based Sequencer (RTEBS) Example Architecture, the RT Sequencer application programming interface (API), and example steps to use with the RTEB Sequencer.

Requirements

This example requires the following support software:

• LabVIEW 8.6 or Later
• LabVIEW Real-Time Module
• Simple TCP/IP Messaging (STM Component)

The tutorial for this architecture can be found at A Real-Time Sequencer Architecture for LabVIEW.

Installation of RT Sequencer API

Download and unzip rtebs_ex.zip to a familiar location.  Close LabVIEW if it is running.  If you do not have the RT Sequencer API already installed, open the RT Sequencer API folder, and double-click setup.exe to begin the installing the RT Sequencer API into the LabVIEW X.x\user.lib\RT Sequencer API directory.

Install Example Steps onto the RT Controller

Steps for the RTEB Sequencer Example must meet the following requirements:  reside on the controller inside an RTEXE, be set as Startup VIs, and located in the c:\ni-rt\startup\Steps folder on the target.  The following are walkthrough instructions for building and deploying RTEB Sequencer Steps.

1. Open rtebs_ex\RT Event-Based Sequencer Design\RT Event-Based Sequencer Design.lvproj.
2. The example steps can be found in the project under the RT Target in the Example Steps Virtual Folder.  Refer to Figure 1.
3. Change the IP address of RT Target by right-clicking on it and choosing Properties.
4. In the General Category change the IP address from 10.0.36.164 to your targets IP address and click OK.
5. Inside the project expand Build Specifications for RT Target
6. Right-click on All Steps and choose Properties.
7. Inside the Build Specification there are a few key selections to note. 
   • In the Information Category choose where you want the steps to build to on your host computer.
   • In the Source Files Category notice how INI Test.vi, Generate100.vi, and CPU Step.vi and BlinkTest.vi are set to be Startup VIs.  To make it so that a VI is a step you MUST make it a Startup VI.  This does not make it so that VI begins when the controller is rebooted, but does set a property in the RTEXE that makes the VI easier to find.
   • In the Destinations Category notice that the final executable named Steps.rtexe has a Destination path of c:\ni-rt\startup\Steps.  This is the default path where steps will be located.
8. Click the Build button.
9. Right-click All Steps and choose Deploy.  You could receive a conflict message talking about the executable not being set to automatically launch.  Click OK as this is expected.  Now the Steps have been loaded onto your real-time controller.

Figure 1.  There are four example steps that demonstrate how to use the RT Sequencer API.

Running the RT Sequencer

The RT Event-Based Sequencer Design Folder contains the all the VIs for the host program (RTEB Sequencer –Host.vi) and the target program (RTEB Sequencer – Target.vi).

1. Begin by opening RT Event-Based Sequencer Design.lvproj (if you have not already) which is the LabVIEW project for the RTEB Sequencer Architecture.
2. Change the IP Address of target inside the project by right-clicking RT Target and selecting Properties.
3. With the General Category selected change the IP address to that of your target and click OK.
4. Under RT Target, open RTEB Sequencer – Target.vi and press the run button.  The VI should be downloaded to your target.
5. Under My Computer, open the RTEB Sequencer – Host.vi and press the run button.  In the status window you should see text indicating that the program was started.
6. Type in the IP Address of the target into the IP Address control.  Click the Connect button.  The Steps in Sequence control should populate with steps that are loaded onto the controller.  You should also see the Heartbeat control blink.
7. As the steps sequence through their order the Status window should update.
8. If the BlinkTest.vi is running, LEDs on you real-time controller should blink.  If you are running Generate100.vi then you should see the status window count down from 10. The INI Test step grabs a number from the Sequencer.ini file (located in rtebs_ex\RT Event-Based Sequencer Design) and sends it to the target.  The target then counts down from number it received.  

 

Requirements

Filename: rtebs_ex.zip

Software Requirements

Application Software: LabVIEW Professional Development System 8.6
Toolkits and Add-Ons: LabVIEW Real-Time Module 8.6
Language(s): LabVIEW

Hardware Requirements

Hardware Group: PXI/CompactPCI, Compact FieldPoint, CompactRIO, Real-Time (RT)

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