ProSoft Technology MVI69E-MBS - Manual (Page 144)

Reference MVI69E-MBS ♦ CompactLogix Platform
User Manual Communication Module
Page 144 of 162 ProSoft Technology, Inc.
January 6, 2014
7.4.15 Pass-through Formatted Block for Function 5
Block 9958: Pass-through Formatted Block for Function 5
Block 9958: Request from Module to Processor
Offset Description
0 Read Block ID: 9958
1 Write Block ID: 9958
2 Number of word registers in Modbus data set
3 Starting address for Modbus data set
4 to (n+1) Data (Length in words = n - 2)
Where n = 60, 120, or 240 depending on the Block Transfer Size parameter.
The ladder logic is 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 an
output image write block with the following format.
Block 9958: Response from Processor to Module
Offset Description
0 Write Block ID: 9958
1 to n Spare (Length in words = n - 2)
This informs the module that the command has been processed and can be
cleared from the pass-through queue.
7.4.16 Pass-through Formatted Block for Function 15
Block 9959: Pass-through Formatted Block for Function 15
When the module receives a function code 15 in pass-through mode, the module
writes the data using block ID 9959 for multiple-bit data. First the bit mask clears
the bits to be updated. This is accomplished in RSLogix 5000 by ANDing the
inverted mask with the existing data.
Next, the new data ANDed with the mask is ORed with the existing data. This
protects the other bits in the INT registers from being affected. This function can
only be used if the Block Transfer Size parameter is set to 120 or 240 words.