ProSoft Technology MVI69E-MBTCP - Manual (Page 140)

Reference MVI69E-MBTCP ♦ CompactLogix Platform
User Manual Modbus TCP/IP Enhanced Communication Module
Page 140 of 150 ProSoft Technology, Inc.
May 20, 2015
The ladder logic is responsible for parsing and copying the received message
and performing the proper control operation as expected by the client device.
The processor must then respond to the Pass-Through control block with an
output image write block with the following format. This informs the module that
the command has been processed and can be cleared from the Pass-Through
queue.
Block 9958: Response from Processor to Module
Offset Description
0 Write Block ID 9958
1 to n Spare (Length in words = n - 2)
7.4.15 Pass-Through Formatted Block for Function 15 (9959)
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.
Block 9959: Request from Module to Processor
Offset Description
0 Read Block ID 9959
1 Write Block ID 9959
2 Length in words
3 Data address
4 to 28 Modbus Data
29 to 53 Bit mask to use with the data set. Each bit to be considered with the data set have
a value of 1 in the mask. Bits to ignore in the data set have a value of 0 in the
mask.
54 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 client device.
The processor must then respond to the Pass-Through control block with a write
block with the following format. This informs the module that the command has
been processed and can be cleared from the Pass-Through queue.