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DeltaV Serial Card Mapping

Each Connection Definition requires at least one dataset to be configured to hold the data exchanged with the field device. Up to 10 datasets may be assigned to a connection definition. The EtherNet/IP Interface Definition should be configured before the serial card mapping is completed.

Each dataset direction may be set to input, output, or output w/read-back, depending on how the data is to be accessed in DeltaV.  The direction of the dataset should match the direction of the data in the field device.  For example, the Allen Bradley Logix processors will place input data and output data in independent tags, so the readback flag should be unchecked for output datasets.

Figure 1 - Connection Definition Dialog with Dataset Configuration Tab Visible

DeltaV Access Definitions

This section configures the datasets that are used to pass data to and from the communications buffers.  There is always at least one dataset, the base dataset.  There can be a maximum of 10 datasets for a single connection definition. Table 1 gives the definition of each column in the dataset list.

Column Name Description
DS This is the index of the dataset associated with this connection. The index is zero based. The index is used by the mapping elements.
Data Type This gives the data direction (Table 3) and the data type (Table 2) of the registers.
Input This column gives the number of input registers that have been used by the mapping elements.
Output This column gives the number of output registers that have been used by the mapping elements.

Table 1 - Dataset Parameters

The Add button will add another dataset to the list. An existing dataset's properties can be edited by double-clicking on its row in the table. In both cases, Figure 2 will appear. The data direction cannot be changed if there are already mapping elements using the dataset.

Figure 2 - Dataset Properties

Datasets can be deleted by selecting the dataset to remove from the list and clicking Delete. Only datasets that have no mapping elements can be deleted. There must always be at least one dataset.

Byte Order

The VIM is able to change the byte order as it moves data from the EtherNet/IP connection buffers to the IO cards data structures. Normally the default byte order is correct. There are very few devices that require changes to this setting.

Given an example four byte value, B1 B2 B3 B4, the four byte swapping options perform the actions given in Table 4.

Option Byte Order
Swap words and bytes (default) B4 B3 B2 B1
Leave words unswapped B1 B2 B3 B4
Swap words, leave bytes B3 B4 B1 B2
Swap bytes, leave words B2 B1 B4 B3

Table 4 - Byte Order

User Controls Mapping

This is a copy of the User Controls Mapping parameter from the EtherNet/IP Interface Definition tab.

EtherNet/IP Buffer to Dataset Mapping

For some connection types, the dataset registers must be mapped to bytes in the connection definition. The right side of Figure 1 contains Mapping Elements that define how the bytes from the EtherNet/IP buffers are copied to the DeltaV serial card dataset registers. Each row represents one mapping element. A mapping element copies a contiguous number of bytes to a contiguous set of registers.

There are two sets of mapping elements: one for inputs to DeltaV and the other for outputs from DeltaV. The mapping element parameters are the same for both directions.

EtherNet/IP Buffer Mapping Buttons

Column Name Description
Element This is the mapping element number.
EtIP Buf

This is the starting byte offset into the EtherNet/IP buffer. The first byte in the EtherNet/IP buffer is at offset zero.

For example, if this value were zero and Bytes were equal to 20, then the mapping element would be working with bytes 0 through 19 in the buffer.

Type This is the data type of the mapping element. It is copied from the dataset that is selected when defining the mapping element. The data type determines how many bytes the VIM associates with a given register in a dataset.
Dataset This is the dataset index, from DeltaV Access Definitions. If input, data will be copied from the EtherNet/IP buffer to this dataset. If output, data will be copied from this dataset to the EtherNet/IP buffer.
Offset

This is the starting byte offset in the DeltaV dataset for the mapping element.

DeltaV register number = <offset> / <bytes per register> + 1

For example, if the data type were 16-bit Integer and the offset was 10, the first register for this mapping element would be R6 in DeltaV.

Bytes

This is the number of bytes copied by the mapping element.

DeltaV registers copied = <bytes> / <bytes per register>

Table 5 - Mapping Element List

EtherNet/IP Input Buffer Map

Figure 3 - EtherNet/IP Input Buffer Map Dialog

EtherNet/IP Output Buffer Map

Figure 4 - EtherNet/IP Output Buffer Map

EtherNet/IP Buffer Fields

This dialog is used to name individual registers in an EtherNet/IP buffer map. The names are not used by DeltaV, but they are visible in VIMNet Diagnostics.

Figure 5 - EtherNet/IP Buffer Map Field Names

EtherNet/IP Buffer Field Columns
Column Description
Name

This is the name of the field

Data Type

This is the DeltaV Data Type of the field.

It dictates how many bytes each element (i.e., DeltaV register) uses.

Offset

This is the offset, in bytes, from the beginning of the dataset for this fields. This number must not leave the range defined in the map.

Elements

This is the number of elements (i.e., DeltaV registers) that this field uses.

This number, times the number of bytes defined by the Data Type, determine the total length of the field.

Table 6 - EtherNet/IP Buffer Field Columns

Messaging Type Specific Dataset Notes

Each messaging type has specific requirements on how the datasets must be configured. See the topics below for more information.