MVI56-MNETCR ♦ ControlLogix Platform
Reference
Modbus TCP/IP Multi Client Communication Module for Remote Chassis
User Manual
ProSoft Technology, Inc.
Page 99 of 127
February 14, 2011
5.3.1 Client Driver
In the client driver, the MVI56-MNETCR module issues read or write commands
to servers on the Modbus TCP/IP network using 30 simulated clients. These
commands are user configured in the module via the Client Command List for
each client received from the module's configuration file (MNET.CFG) or issued
directly from the 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 associated table describe the flow of
data into and out of the module.
Step
Description
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.
2
When configured, the client driver begins transmitting read and/or write commands to the
other nodes on the network. If writing data to another node, the data for the write
command is obtained from the module's internal database to build the command.
3
Presuming successful processing by the node specified in the command, a response
message is received into the client driver for processing.
4
Data received from the node on the network is passed into the module's internal
database, assuming a read command.
5
Status data is returned to the processor for the client and a Command List error table
can be established in the module's internal database.
