ProSoft Technology MVI56E-MNETC User Manual page 111

MVI56E-MNETC/MNETCXT ♦ ControlLogix Platform
Modbus TCP/IP Client Enhanced Communication Module - Client/Server
Block Request from Module to Processor
Word Offset
0
1
2 to 248
249
Ladder logic subtracts 1000 from the value contained in word 249 to determine a
block index. This bock index determines which 200-word block of data will be
taken from the ReadData array and placed in the output image to be returned to
the module.
Block Response from Processor to Module
Word Offset
0
1 to 200
201 to 247
Event Command Blocks (2000 to 2029)
Note: To use the Event Command Block for polling operations, you must configure at least one
command in the Client even if the command is disabled.
During routine operation, the module continuously cycles through the user-
defined MNET Client x Commands (page 44) for each Client, examining
commands in the order they are listed, and sending enabled commands on the
network. However, the module also has a special command priority queue, which
is an internal buffer that holds commands from special function blocks until they
can be sent on the network.
When one or more commands appear in the command priority queue:
1 The routine polling process is temporarily interrupted.
2 The commands in the command priority queue are executed until the queue
is empty.
3 Then the module goes back to where it left off on the MNET Client x
Command List and continues routine polling.
Event Command blocks send Modbus TCP/IP commands directly from controller
tags by ladder logic to the Client command priority queue on the module. Event
Commands are not placed in the module's internal database and are not part of
the MNET Client x Command List.
ProSoft Technology, Inc.
September 20, 2018
Description
Reserved
1000 to 1049
Spare
1000 to 1049
Description
1000 to 1049
Output data to preset in module.
Spare
Reference
User Manual
Length
1
1
247
1
Length
1
200
47
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