ProSoft Technology MVI56E-MNETR - Manual (Page 115)

Reference MVI56E-MNETR ♦ ControlLogix Platform
User Manual Modbus TCP/IP Interface Module with Reduced Data Block
ProSoft Technology, Inc.
Page 115 of 153
August 31, 2009
following illustration describes the data flow for a slave port with pass-through
enabled:
0
4999
40001
45000
Modbus
Addresses
Database
Addresses
ControlLogix
Controller Tags
Server
Driver
Status
Status
from Module
Register
Data
storage
Register
Data
Processor Memory MNetR Module Backplane Interface
Configuration
Status
Read Functions
Write Functions
Client Driver
In the client driver, the MVI56E-MNETR module issues read or write commands
to servers on the Modbus TCP/IP network. These commands are user configured
in the module via the Client Command List received from the module's
configuration file (MNET.CFG) or issued directly from the ControlLogix processor
(event command control). Command status is returned to the processor for each
individual command in the command list status block. The location of this status
block in the module's internal database is user defined. The following flow chart
and table describe the flow of data into and out of the module.
Client
Driver
MNetR Memory
Configuration
Client
Command List
Status
3
1
2
4
5
0
4999
40001
45000
Modbus
Addresses
Database
Addresses
ControlLogix
Controller Tags
Status
Status
from Module
Register
Data
storage
Register
Data
Processor Memory Backplane Interface
Event Cmd
Data
Event Cmd
Data
Event Cmd
Data
Command
Control
Command
Control
Command
Control
4
1 The client driver obtains configuration data from the MNET.CFG file when the
module restarts. The configuration data obtained includes the timeout
parameters and the Command List. These values are used by the driver to
determine the type of commands to be issued to the other nodes on the
Modbus TCP/IP network.