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What are the advantages or limitations of linking the variable in Vijeo Designer to a Unity Pro *.XVM or *.STU file?

Published date: 28 January 2019

What are the  limitations of linking the variable in Vijeo Designer to a Unity Pro *.XVM or *.STU file?

Product Line:
Unity Pro, Vijeo Designer, link variables




Below are the limitations when linking unlocated and located variables from Unity Pro:

  • DDT Unlocated and DDT Located variable addresses are imported into Vijeo Designer as PLC Internal References. PLC Internal References are identified with a %UV or %UI at the beginning of the address (see table below). Although the PLC Internal Reference address is named differently than the Unity DDT's address, they are the same address. The addresses cannot be altered in Vijeo Designer.

  • The device addresses for the elements of structure and array variables (located or unlocated) are automatically extracted from the Unity XVM and STU files and cannot be altered in the editor.

  • Array and DDT structure addresses (located and unlocated) are always imported as unlocated in Vijeo Designer.

  • You must update the links to all unlocated variables any time you make a change to the PLC. Unlike normal variable addressing where there is a defined register to store a value (for example, %MW5), values for unlocated variables in a PLC are stored in memory locations assigned by Unity Pro. These memory locations have internal memory addresses (for example, %UV46.2.16.255.INT.20464430). Each time a change is built in Unity Pro, the internal memory addresses of the unlocated variables are regenerated and different from the last build. When you are satisfied with your changes to the PLC project after building and downloading to the PLC, make sure you save a new STU file or export a new XVM file, and update the variable link in your Vijeo Designer project.

  • Function Block <input/output> parameters linked in Vijeo Designer as unlocated variables are read-only. For more information regarding the IEC 61131-3 Function Block Diagram (FBD) language and its use in Unity Pro software, please refer to the Unity Pro online help.

  • Unlocated variables are unaffected by the Double Word word order and ASCII Display byte order configuration settings in Schneider Electric drivers. These configuration settings are automatically defined by the protocol.

  • Unity BOOL %MWi.j variables are converted to BOOL %MWi.Xj variables while Unity BOOL %MWi variables are converted to UNIT %MWi variables in Vijeo Designer.

  • Vijeo Designer does not support Unity Date and Time (DT) types. The New Variables From Equipment dialog box will not list the DT data types from Unity Pro. If any Unity Pro data types use the DT variable as an element, the data type will not be listed in the New Variables From Equipment dialog box.

  • DDT variables do not support indirect addressing.

  • Vijeo Designer does not support anonymous arrays of more than two dimensions. To link to an array with more than two dimensions, you must define a derived data type array in Unity Pro.

  • When importing IODDT variables for Unity Pro, use the STU format.

  • Array indexes start at 0 in Vijeo Designer; however, Unity Pro array indexes can start with any value. Imported Unity Pro arrays are modified so their start index is 0. For example, a Unity Pro array going from 5 to 15 is changed to go from 0 to 10 after importing into Vijeo Designer.

  • Derived Function Blocks from Unity STU and XVM files are imported into Vijeo Designer as unlocated structure variables.

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