ProSoft Technology MVI69-ADM - Manual (Page 36)

Understanding the MVI-ADM API MVI-ADM ♦ 'C' Programmable
Developer's Guide 'C' Programmable Application Development Module
Page 36 of 342 ProSoft Technology, Inc.
February 20, 2013
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 200 words (block offsets 2 to 201) of
data. In addition to moving user data, the block also contains status data for the
module. This last set of data is transferred with each new block of data and is
used for high-speed data movement.
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 network or operator
control through the module’s Configuration/Debug port.
Module Configuration Data Transfer Block (9000)
When the module performs a restart operation, it will request configuration
information from the ControlLogix processor. This data is transferred to the
module in specially formatted write blocks (output image). The module will poll for
each block by setting the required write block number in a read block (input
image).
This block sends general configuration information from the processor to the
module. The data is transferred in a block with an identification code of 9000.
The structure of the block is shown in the following table.
Offset Description Length
0 9000 1
1 to 6 Backplane Set Up 6
7 to 15 Port 1 Configuration 9
16 to 24 Port 2 Configuration 9
25 to 247 Spare 223
The read block used to request the configuration has the following structure:
Offset Description Length
0 Reserved 1
1 9000 1
2 Module Configuration Errors 1
3 Port 1 Configuration Errors 1
4 Port 2 Configuration Errors 1
5 to 248 Spare 244
249 -2 or -3 1
If there are any errors in the configuration, the bit associated with the error will be
set in one of the three configuration error words. The error must be corrected
before the module starts operating.