Creating a Modbus Device Type

A Modbus device type translates between the register based data structure on the Modbus device and the ION based data structure in Power Monitoring Expert.

When you create the device type with the Device Type Editor, you first define the Modbus registers that you want to access on the device, and then you map these registers to ION managers, modules, and registers. You can enter the Modbus register information manually in the Device Type Editor user interface, or use Microsoft Excel to define the register list and then copy and paste it into the Device Type Editor. The mapping of Modbus to ION registers is done by dragging Modbus registers onto ION registers, or the reverse, using the mouse pointer.

Prerequisites

To create a device type for a device, you need to know the details of its Modbus register map. At a minimum, you need the Modbus addresses, data formats, and possible scaling values for the measurements you want to access on the device. You can get this information from the device documentation or the device manufacturer.

NOTE: Before creating a new device type with the Device Type Editor, check if it is available as a pre-configured device type or as a downloadable add-on.

References

See the following references for information on how to use the Device Type Editor or information related to Modbus register definitions:

To create a Modbus device type:

  1. In Device Type Editor, click File > New > Modbus Device Type to open a New Mapping template.
  2. Enter the Modbus register information into the Modbus Map table in the right display pane, in one of two ways:
    • Add each Modbus register manually in the Device Type Editor, using the available editing controls (right-click to open the context menu).
    • Use Microsoft Excel to define the register list, copy it, and paste it into the Modbus Map table.

      NOTE: The register list columns in the Excel sheet must match the column content and positions in the Device Type Editor Modbus Map table. Confirm that the format entries match one of the supported Modbus Data Formats and that there are no spelling mistakes, such as added space characters or different capitalization.

  3. Map each Modbus register in the Modbus Map to a measurement in the Measurement Tree in the left pane. To see the measurements in the tree, expand the managers and modules, for example Current > Phase Current > Current A,B,C, ... . Map the registers in one of two ways:
    • Using the mouse, drag the measurement you want to map in the Measurement Tree onto the corresponding measurement in the Modbus Map.
    • Using the mouse, drag the Modbus register you want to map in the Modbus Map onto the corresponding measurement in the Measurement Tree.

    NOTE: If you cannot find a suitable measurement in the Measurement Tree, add a new manager, module, and register to represent this measurement. To do this, right-click any of the existing managers in the Measurement Tree and choose the appropriate menu options.

  4. Configure the device type name and template name.
    1. In the Measurement Tree, click Factory Information > Factory 1 > FAC1 Device Type to open the String Register Details dialog for this register. In String Register Details, enter a device type name in the Value box. This name will be visible in the Management Console when you select a device type for a new device. Choose a name that identifies the device, but does not match any of the existing device types.

      Example: For a device called "PM123", you could use a device type name of "DTE_PM123". The device type name does not have to include DTE, but it is a good practice to choose a string that identifies this device type as a DTE type.

    2. In the Measurement Tree, click Factory Information > Factory 1 > FAC1 Template to open the String Register Details dialog for this register. In String Register Details, enter a template name in the Value box. This name is used to match your new device type with a default Vista diagram, if you choose to create such a diagram. The template name should include the device type name followed by a version number that represents the version of your new device type.

      Example: For a device type called "DTE_PM123", you could use a template name of "DTE_PM123_V1.0.0".

  5. (Optional) Click Tools > Clean Measurement Tree to remove any Measurement Tree elements that have not been mapped to Modbus registers. This makes it easier to find the relevant measurements in the Measurement Tree in Vista or OPC clients for example.
  6. Click File > Save, to save the new device type.
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