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RSLogix 5000 Class 1 ENBT Configuration

Each dataset in DeltaV corresponds to a specific ENBT module in the Logix controller. Configuration of an ENBT module is described below. The Logix controller manages data updates for an ENBT dataset, i.e., the Logix is the Master in this communication. The VIM merely receives the data and sends it up to the DeltaV controller. By nature, this mechanism is very fast, and suitable for high-speed data transfers from the Logix I/O sub-system into DeltaV.

To create an ENBT dataset in DeltaV, follow these steps:

  1. Create the DeltaV dataset as Output with Readback. The DeltaV data type can be any supported type and should match the data type in the Logix module (Step 8 below). Note that the DeltaV data type of Floating point with status is the same as the Logix module data type of Real.

  2. Set the Device Data type in DeltaV to 15. Use starting address as 0 and the maximum number of values as 100. The number of values should also match the Logix module size. You can use fewer values than 100. If the dataset is of type floating point, then the maximum number of values is 50.

  3. In the RSLogix 5000 system, right click on I/O configuration as shown below and select New Module.

    Figure 1 - I/O Configuration Context Menu - New Module

  4. When New Module is selected, the following dialog will appear. Select the Ethernet Interface card appropriate for your PLC.

    In this guide, we are configuring an 1756-ENBT/A for a ControlLogix processor.

    Figure 2 - Select Parent Ethernet Module Type

  5. Configure the ENET parent as shown below. The specified IP address is for the Logix Ethernet card. The Slot number must match where in the chassis the card resides. Select all other parameters as shown.

    Figure 3 - Parent Ethernet Module Properties

  6. Next, right click on the ENET parent and select New Module. Then from the list provided, select and add a new 1756-ENBT module as shown.

    This module corresponds to the VIM card. Regardless of the parent ENBT card type, this one should be a 1756-ENBT/A. Other interface card types may result in undesired behavior.

    Figure 4 - Select VIM Ethernet Module

  7. Configure the module as shown below. The specified IP address is for the VIM card.

    Specify the Slot number as 0, and the Chassis size as 32. This will allow you to add a maximum of 32 ENBT connections into the VIM. Select all other parameters as shown.

    It is very important that Comm Format and Electronic Keying are set as shown, if they are not, the VIM will not be able to communicate with the PLC.

    Figure 5 - VIM Ethernet Module Properties

  8. Right-click on the VIM Ethernet Module and select New Module.

    This will be the module that represents the DeltaV Dataset in the Logix configuration.

    Figure 6 - VIM Ethernet Module Context Menu

  9. From the presented list of modules, select the 1756-Module as shown below.

    Always select the 1756-MODULE, using any other module type may result in undesired behavior.

    Figure 7 - Select Dataset Ethernet Module

  10. Specify the properties of the 1756-Module.

    This module is equivalent to the DeltaV dataset. Specify the Name corresponding to the DeltaV dataset or some other meaningful string.


    Figure 8 - Dataset Ethernet Module Properties

  11. In the Assembly Instance column, the Input and Output parameters are the dataset index numbers. In this example, these are specified as 1. Valid range for these parameters is 1-128. This parameter is calculated based on the target card/dataset to which the ENBT is mapped. For example, if the VIM is emulating serial cards 57-60, then the following applies, where each card has 32 datasets:

    Serial Card Serial Card Calculated Assembly Instance Range













    Table 1 - Assembly Instance Specification


  12. The Input and Output Size Parameters should match the number of values in the DeltaV dataset. Configuration parameters should always be specified as shown. Lastly, specify the Comm Format. The Comm format corresponds to the DeltaV data type. For example, INT corresponds to 16-bit unsigned int.

    Do not use any data type other than an array of a basic type.

    The VIM does not support user-defined data types.

  13. Click Next to specify the Requested Packet Interval. The following dialog is shown. Specify the time as 400ms.

    This parameter specifies how frequently the Logix will update the VIM. For few (less than 8) datasets, an RPI of 200ms may be used. For more than 16 datasets, the RPI may have to be adjusted up to the maximum (slowest) rate of 750ms. Click Finish, to complete the module configuration.

    Configuring an RPI of less than 100ms is not recommended. The VIM will not be able to keep up with messages from Logix, causing datasets to have bad status.

    Figure 9 - Dataset Module RPI

  14. Create the 1756-MODULE for the second DeltaV Dataset

    Note that this module is configured for DeltaV dataset 2, and has a Comm Format of REAL. This corresponds to a DeltaV dataset of type floating point, with a maximum of 50 registers.

    Figure 10 - Add the Ethernet Module for a Floating-Point Dataset

  15. The final configuration with 2 ENBT connections will appear as follows:

    Figure 11 - Final RSLogix 5000 IO Configuration for a ControlLogix Processor