Normal Data Transfer - ProSoft Technology MVI56-PNPM User Manual

Reference
As shown in the diagram above, all data transferred between the module and the
processor over the backplane is through the input and output images. Ladder
logic must be written in the ControlLogix processor to interface the input and
output image data with data defined in the Controller Tags. All data used by the
module is stored in its internal database. This database is defined as a virtual
data table with addresses from 0 to 6999. The following illustration shows the
layout of the database:
Data contained in this database is paged through the input and output images by
coordination of the ControlLogix ladder logic and the MVI56-PNPM module's
program. Up to 248 words of data can be transferred from the module to the
processor at a time. Up to 247 words of data can be transferred from the
processor to the module. Each image has a defined structure depending on the
data content and the function of the data transfer as defined below.

5.2.4 Normal Data Transfer

Normal data transfer includes the paging of the user data found in the module's
internal database in registers 0 to 4999 and the status data. These data are
transferred through read (input image) and write (output image) blocks. Refer to
the Module Set Up section for a description of the data objects used with the
blocks and the ladder logic required. The structure and function of each block is
discussed below.
Read Block
These blocks of data transfer information from the module to the ControlLogix
processor. The structure of the input image used to transfer this data is shown in
the following table:
Offset
0
1
2 to 201
ProSoft Technology, Inc.
January 2, 2008
Phantom Network Protocol Master Communication Module
Module's Internal Database Structure
5000 registers for user data
2000 words of configuration
and status data
Description
Reserved
Write Block ID
Read Data
MVI56-PNPM ♦ ControlLogix Platform
0
Register
Data
4999
5000
Status
and
Config
6999
Length
1
1
200
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