ProSoft Technology MVI56E-MCM/MCMXT - Manual (Page 126)

Reference MVI56E-MCM ♦ ControlLogix Platform
User Manual Modbus Communication Module
Page 126 of 199 ProSoft Technology, Inc.
June 18, 2014
Block Request from Processor to Module
Word Offset Description Length
0 5001 to 5006 or 5101 to 5106 1
1 Command index (MCM.CONFIG.P ORT XM ASTER C MD [command
index value])
1
2 Command index (MCM.CONFIG.P ORT XM ASTER C MD [command
index value])
1
3 Command index (MCM.CONFIG.P ORT XM ASTER C MD [command
index value])
1
4 Command index (MCM.CONFIG.P ORT XM ASTER C MD [command
index value])
1
5 Command index (MCM.CONFIG.P ORT XM ASTER C MD [command
index value])
1
6 Command index (MCM.CONFIG.P ORT XM ASTER C MD [command
index value])
1
7 to 247 Spare 241
Blocks in the range of 5001 to 5006 are used for Modbus Port 1, and blocks in
the range of 5101 to 5106 are used for Modbus Port 2. The last digit in the block
code defines the number of commands to process in the block. For example, a
block code of 5003 contains 3 command indexes for Modbus Port 1. The
Command index parameters in the block have a range of 0 to 99 and correspond
to the Master command list entries.
The module responds to a Command Control block with a block containing the
number of commands added to the command queue for the port. The following
table describes the format for this block.
Block Response from Module to Processor
Word Offset Description Length
0 Reserved 1
1 Write Block ID 1
2 Number of commands added to command queue 1
3 to 248 Spare 246
249 5000 to 5006 or 5100 to 5106 1
Configuration Data Transfer
When the module performs a restart operation, it will request configuration
information from the ControlLogix processor. This data is transferred to the
module in specially formatted write blocks (output image). The module will poll for
each block by setting the required write block number in a read block (input
image). Refer to Using the Sample Program in an Existing Application (page 186)
for a description of the data objects used with the blocks and the ladder logic
required. The format of the blocks for configuration is given in the following
topics.