ProSoft Technology MVI69-MCM - Manual (Page 108)

Reference MVI69-MCM ♦ CompactLogix or MicroLogix Platform
User Manual Modbus Communication Module
Page 108 of 167 ProSoft Technology, Inc.
March 22, 2011
The following illustration shows the data transfer method used to move data
between the CompactLogix or MicroLogix processor, the MVI69-MCM module
and the MODBUS network.
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
CompactLogix or MicroLogix 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. The following illustration shows the layout of the
database:
Module’s Internal Database Structure
5000 registers for user data 0
Register Data
4999
3000 words of configuration and
status data
5000
Status and Config
7999