ProSoft Technology MVI69L-MBS - Manual (Page 70)

MVI69L-MBS Backplane Data Exchange MVI69L-MBS ♦ CompactLogix Platform
User Manual Communication Module
Page 70 of 154 ProSoft Technology, Inc.
January 6, 2014
4.3 Normal Data Transfer
Normal data transfer includes the paging of the user data found in the module’s
internal database and the status data. These data are transferred through read
(input image) and write (output image) blocks. The following topics describe the
structure and function of each block.
4.3.1 Write Block: Request from the Processor to the Module
These blocks of data transfer information from the processor to the module. The
structure of the output image used to transfer this data is shown below:
Offset Description Length (words)
0 Write Block ID 1
1 to 240 Write Data 240
The Write Block ID is an index value used to determine the location in the
module’s database where the data is placed.
4.3.2 Read Block: Response from the Module to the Processor
These blocks of data transfer information from the module to the processor. The
structure of the input image used to transfer this data is shown below:
Offset Description Length (words)
0 Read Block ID 1
1 Write Block ID 1
2 to 241 Read Data 240