ProSoft Technology ControlLogix inRAx MVI56E-MNETR User Manual page 116

Reference
User Manual
Block Response from Module to Processor
These blocks of data transfer information from the module to the ControlLogix
processor. The following table describes the structure of the input image.
Offset
0
1 to 40
41
The Read Block ID is an index value used to determine the location of where the
data will be placed in the ControlLogix processor controller tag array of module
read data. Each transfer can move up to 40 words (block offsets 1 to 40) of data.
In addition to moving user data, the block also contains status data for the
module.
The Write Block ID associated with the block requests data from the ControlLogix
processor. Under normal program operation, the module sequentially sends read
blocks and requests write blocks.
For example, if the application uses three read and two write blocks, the
sequence will be as follows:
R1W1→R2W2→R3W1→R1W2→R2W1→R3W2→R1W1→
This sequence will continue until interrupted by other write block numbers sent by
the controller or by a command request from a node on the Modbus network or
operator control through the module's Configuration/Debug port.
Initialize Output Data
When the module performs a restart operation, it will request blocks of output
data from the processor to initialize the module's output data (Read Data Area).
Use the Initialize Output Data parameter in the configuration file to bring the
module to a known state after a restart operation. The following table describes
the structure of the request block.
Offset
0
1 to 40
41
Page 116 of 175
Description
Write Block ID
Read Data
Read Block ID
Description
1000 to 1124
Spare
1000 to 1124
MVI56E-MNETR ♦ ControlLogix Platform
Modbus TCP/IP Interface Module with Reduced Data Block
Length
1
40
1
Length
1
40
1
ProSoft Technology, Inc.
June 14, 2011