ProSoft Technology MVI56E-MNETC User Manual
Page 115
MVI56E-MNETC ♦ ControlLogix Platform
Reference
Modbus TCP/IP Client Enhanced Communication Module
User Manual
ProSoft Technology, Inc.
Page 115 of 183
February 3, 2013
Word Offset
Description
Length
241
Product Version
1
242 to 248
Reserved
7
249
Read Block ID
1
The Read Block ID is an index value used to determine where the 200 words of
data from module memory will be placed in the ReadData[x] controller tag array
of the ControlLogix processor. 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. The Write Block ID associated with the block requests
data from the ControlLogix processor.
During 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 contro
l through the module’s Configuration/Debug port.
Status Data in Read Block
The following table describes in more detail the status information found in the
Read Block.
Word Offset
Content
Description
202
Program Scan Count
This value is incremented each time a complete
program cycle occurs in the module.
203
Read Block Count
This field contains the total number of read blocks
transferred from the module to the processor.
204
Write Block Count
This field contains the total number of write blocks
transferred from the processor to the module.
205
Parse Block Count
This field contains the total number of blocks
successfully parsed that were received from the
processor.
206
Command Event Block
Count
This field contains the total number of command
event blocks received from the processor.
207
Command Block Count
This field contains the total number of command
blocks received from the processor.
208
Error Block Count
This field contains the total number of block errors
recognized by the module.
209
Client 0 command
execution word
Each bit in this word enables/disable the commands
for Client 0. If the bit is set, the command will
execute. If the bit is clear, the command will be
disabled. This data is set in the output image
(WriteBlock) from the ladder logic.