ProSoft Technology MVI69-MCM User Manual
Page 128

Reference
MVI69-MCM ♦ CompactLogix or MicroLogix Platform
User Manual
Modbus Communication Module
Page 128 of 167
ProSoft Technology, Inc.
March 22, 2011
Write Block - Command Control
Here is the structure of the Command Control output image write block.
Offset
Description
Length (words)
0
5001 to 5006 or 5101 to 5106
1
1
Command index
1
2
Command index
1
3
Command index
1
4
Command index
1
5
Command index
1
6
Command index
1
7 to ( n )
Spare
( n ) = 60, 120, or 240 depending on the Block Transfer Size parameter (refer to the configuration
file).
Blocks in the range of 5001 to 5006 are used for Port 1, and blocks in the range
of 5101 to 5106 are used for 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 that are for Port 1. The Command index
parameters in the block have a range of 0 to 99 and correspond to Master
Command List entries.
The module responds to a Command Control write block with a input image read
block containing the number of commands added to the command queue for the
port.
Read Block - Command Control
Here is the structure of the Command Control input image read block.
Offset
Description
Length (words)
0
5000 to 5006 or 5100 to 5106
1
1
Write Block ID
1
2
Number of commands added to command queue
1
3 to ( n + 1 )
Spare
( n ) = 60, 120, or 240 depending on the Block Transfer Size parameter (refer to the configuration file).