ProSoft Technology MVI69-MCM User Manual
Page 130

Reference
MVI69-MCM ♦ CompactLogix or MicroLogix Platform
User Manual
Modbus Communication Module
Page 130 of 167
ProSoft Technology, Inc.
March 22, 2011
Function 5
Here is the structure of the input image write block for Formatted Pass-Through
Control Block ID 9958.
For MVI69-MCM firmware versions 1.21 and newer only:
Offset
Description
Length (words)
0
9958
1
1
9958
1
2
Number of words
1
3
Data Address
1
4 to ( n + 1 )
Data
( n - 2 )
For MVI69-MCM firmware versions earlier than 1.21:
Offset
Description
Length (words)
0
0
1
1
9958
1
2
Length
1
3
Data Address
1
4 to ( n + 1 )
Data
( n - 2 )
The ladder logic will be responsible for parsing and copying the received
message and performing the proper control operation as expected by the Master
device. The processor must then respond to the pass-through control block with
a output image write block with the following format.
Offset
Description
Length (words)
0
9958
1
1 to ( n )
Spare
( n )
This will inform the module that the command has been processed and can be
cleared from the pass-through queue.
( n ) = 60, 120, or 240 depending on the Block Transfer Size parameter (refer to the configuration file).