ProSoft MVI56E-MNETCR User Manual page 111

MVI56E-MNETCR ♦ ControlLogix Platform
Modbus TCP/IP Multi-Client Enhanced Communications Module for Remote Chassis
Event Command Blocks (2000 to 2029)
Note: Event Commands are not needed for normal Modbus command list polling operations and
are needed only occasionally for special circumstances.
During routine operation, the module continuously cycles through the user-
defined MNET Client x Command List (page 49) 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.
Block Request from Processor to Module
Word Offset
0
1 to 4
5
6
7
8
ProSoft Technology, Inc.
Description
Block ID - This word contains the block 2000 to 2029 identification code to
indicate that this block contains a command to execute by the Client driver.
IP Address -These words contain the IP address for the server the message is
intended. Each digit (0 to 255) of the IP address is placed in one of the four
registers. For example, to reach IP address 192.168.0.100, enter the following
values in words 1 to 4  192, 168, 0 and 100. The module will construct the
normal dotted IP address from the values entered. The values entered will be
anded with the mask 0x00ff to insure the values are in the range of 0 to 255.
Service Port - This word contains the TCP service port the message will be
interfaced. For example, to interface with a MBAP device, the word should
contain a value of 502. To interface with a MNET device, a value of 2000
should be utilized. Any value from 0 to 65535 is permitted. A value of 502 will
cause a MBAP formatted message to be generated. All other values will
generate an encapsulated Modbus message.
Slave Address - This word contains the Modbus node address for the
message. This field should have a value from 0 to 41.
Internal DB Address - This word contains the internal Modbus address in the
module to use with the command. This word can contain a value from 0 to
4999.
Point Count - This word contains the count parameter that determines the
number of digital points or registers to associate with the command.
Reference
User Manual
Page 111 of 161