ProSoft MVI69E-MBS - Pass-Through Block for Function 99 (9970)

Reference MVI69E-MBS ♦ CompactLogix Platform
User Manual Modbus Serial Enhanced Communication Module
Page 142 of 154 ProSoft Technology, Inc.
June 28, 2017
7.4.18 Pass-through Block for Function 99 (9970)
Block 9970: Pass-Through Block for Function 99
Block 9970: Request from Module to Processor
Offset
Description
0
Read Block ID: 9970
1
Write Block ID: 9970
2
1
3
0
4 to (n-1)
Spare
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 9970: Response from Processor to Module
Offset
Description
0
Write Block ID: 9970
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.