Using Network-Published Shared Variables on ARM Targets
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I want to use network-published shared variables to send data between my host computer and an ARM embedded target, such as the MCB2300. How do I need to configure my project to accomplish this?
Shared variable communication between a host computer and an ARM embedded target requires some additional configuration beyond what's normally required between two PC's or a PC and a real-time target. The following tips and tricks should make you successful:
Related Links: Developer Zone Tutorial: New Features in the LabVIEW Embedded Module for ARM Microcontrollers
- Network-published shared variables cannot be hosted on an ARM embedded target. Your shared variable library will have to be hosted on the My Computer target in the LabVIEW project.
- The shared variable library must be deployed before running the PC VI and ARM application. To deploy the variables automatically when you click the Run button, right-click the library and select Autodeploy Variables from the shortcut menu. If you disable autodeployment, you must right-click the project library where a shared variable resides in the Project Explorer window and select Deploy from the shortcut menu to deploy the shared variable.
- Before you deploy an application to the embedded target, you must start the Embedded Variable Connection Manager. The Embedded Variable Connection Manager starts a TCP/IP connection service between the host computer and the ARM target. Select Tools»ARM Module»Embedded Variable Connection Manager to open this utility. Press Start to start the connection service, You can also enable the Embedded Variable Connection Manager to start automatically whenever LabVIEW is launched.
- In the Build Specifications of your embedded application, the Shared Variable Settings category requires the IP address where the Embedded Variable Connection Manager is running. Make sure this IP address is correct when you build your embedded application.
- If you change the IP address of the shared variable host, you must redeploy the variables to the host and rebuild the embedded application. If you use an alias name as the IP address in the build specification, you do not need to modify the build specification for a new IP address, but you still must rebuild the embedded application to resolve the new IP address.
- Eliminate coercion dots on shared variable nodes in VI's that will run on the embedded target.
- Embedded targets do not support the DataSocket Transport Protocol (DSTP). You will receive an invalid input error if you try to use a network-published shared variable that uses DSTP as the connection protocol.
- Network-published shared variables communication requires that the embedded target be networked to the host computer by a crossover cable or through a network hub. Shared variable communication does not occur through the debugging agent.