ProSoft Technology MVI69-MCM User Manual
Page 119

MVI69-MCM ♦ CompactLogix or MicroLogix Platform
Reference
Modbus Communication Module
User Manual
ProSoft Technology, Inc.
Page 119 of 167
March 22, 2011
5.4.6 If Block Transfer Size = 240
5.4.7 Status Data Block (Read Block ID = 0)
After the last Read Block is sent, the module builds an output image (ID = 0) to
transfer the module’s status information to the processor. This information can be
used by the PLC program to determine the current status of the module. Ladder
logic should be constructed to transfer the information in this block to a user data
file. The structure of this block is shown in the following table.
Offset
Content
Description
0
Read Block ID
Block identification code -1 to indicate a status block.
1
Write Block ID
Block requested from the processor by the module.
2
Program Scan Count
This value is incremented each time a complete program
cycle occurs in the module.
3 to 4
Product Code
These two registers contain the product code of "MCM"
5 to 6
Product Version
These two registers contain the product version for the
currently running software.
7 to 8
Operating System
These two registers contain the month and year values for the
program operating system.
9 to 10
Run Number
These two registers contain the Run Number value for the
currently running software.
11
Port 1 Command List
Requests
This field contains the number of requests made from this port
to slave devices on the network.
12
Port 1 Command List
Response
This field contains the number of slave response messages
received on the port.