LabVIEW Datalogging and Supervisory Control Module

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Creating EPICS Server I/O Servers (DSC Module or Real-Time Module)

  • Updated2023-02-21
  • 5 minute(s) read

You can create EPICS Server I/O servers to publish shared variables as process variables (PVs) by using the Channel Access (CA) network protocol.

(Real-Time Module) You can create EPICS Server I/O servers to publish I/O variables (IOVs) as PVs by using the CA network protocol.

Use EPICS Client I/O servers, or third-party EPICS clients, to monitor and update the published PVs after you deploy the processes that contain the shared variables and EPICS Server I/O servers.

Creating EPICS Server I/O Servers Interactively

Complete the following steps to create an EPICS Server I/O server interactively.

  1. In the Project Explorer window, right-click a target, such as the My Computer target, and select New»I/O Server from the shortcut menu.
  2. In the Create New I/O Server dialog box, select EPICS Server and click the Continue button.
  3. In the Configure EPICS Server I/O Server dialog box, click the Add/Remove Variables button to display the Add/Remove Variables dialog box.
    Note  Use the Configure EPICS Server I/O Server dialog box to configure new and existing EPICS Server I/O servers. You can launch this dialog box by right-clicking an EPICS Server I/O server and selecting Properties from the shortcut menu.
  4. In the Access type pull-down menu, specify the access type for the shared variables that you want to add.
  5. In the Add/Remove Variables dialog box, select the shared variables that you want to publish and click the Add button to add these shared variables to the Added Variables list. Press the <Ctrl> key to select multiple shared variables.
    Note  Select a target and click the Add All button to add all supported shared variables under this target. You can select a shared variable from the Added variables list and click the Remove button to remove the shared variable from this list. You also can click the Remove All button to remove all shared variables from this list.
  6. Click the OK button to add the shared variables to the Configure EPICS Server I/O Server dialog box.
  7. (Optional) Triple-click a cell in the PV field to customize PV names for the added shared variables.
    Note  Do not use spaces in the customized PV names. Otherwise, LabVIEW reports these PV names as invalid PV names.
  8. (Optional) Click a cell in the Access type fields to customize access types for the added shared variables.
  9. Click the OK button to create the EPICS Server I/O server.

Creating EPICS Server I/O Servers Programmatically

Complete the following steps to create an EPICS Server I/O server programmatically.

  1. Add the Create EPICS Server VI to the block diagram.

    Add 

  2. Right-click the EPICS Server URL in input of the Create EPICS Server VI and select Create»Constant or Create»Control from the shortcut menu. In the constant or control, specify the location to create the EPICS Server I/O server.
  3. Add the Create PV VI to the block diagram.

    Add 

  4. Wire the EPICS Server ref output of the Create EPICS Server VI to the EPICS Server ref in input of the Create PV VI.
  5. Right-click the variable path input of the Create PV VI and select Create»Constant or Create»Control from the shortcut menu. In the constant or control, specify the path of the shared variable you want to publish to the EPICS Server I/O server.
  6. (Optional) Right-click the PV name input of the Create PV VI and select Create»Constant or Create»Control from the shortcut menu. In the constant or control, specify the name of the process variable for the shared variable you want to publish.
  7. (Optional) Right-click the access type input of the Create PV VI and select Create»Constant or Create»Control from the shortcut menu. In the constant or control, select the access type for the process variable.
  8. (Optional) Specify the data type of the process variable by using one of the following methods:
    Note Note  If the shared variable exists, you do not need to wire the data type input.
    • Wire a data type control or constant, such as a numeric constant, with a default value to the data type input of the Create PV VI. The constant or control you wire to the data type input specifies the data type of the process variable.
    • Wire the shared variable reference to the Variable Property Node, select the Data Type property, and wire the Data Type output of the Variable Property Node to data type input of the Create PV VI.
  9. Add the Deploy EPICS Server VI to the block diagram.

    Add 

  10. Wire the EPICS Server ref out output of the Create PV VI to the EPICS Server ref in input of the Deploy EPICS Server VI.
  11. Run this VI to create and deploy the EPICS Server I/O server and to create a process variable for the shared variable you publish to the EPICS Server I/O server.

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