ProSoft Technology MVI69L-MBTCP - Manual (Page 73)

MVI69L-MBTCP ♦ CompactLogix Platform Backplane Data Exchange
Communication Module User Manual
ProSoft Technology, Inc. Page 73 of 152
January 6, 2014
4.3.2 Client Driver Overview
In Client mode, the MVI69L-MBTCP module issues read or write commands to
server devices on the Modbus network. These commands are user-configured in
ProSoft Configuration Builder Client Command List. This list is transferred to the
module when the module receives its configuration from the processor.
The commands can also be issued directly from the CompactLogix processor
(Special Command Blocks).
Command status is returned to the processor for each individual command in the
command list. The command status list is user-defined in module memory. Below
describes the flow of command data into and out of the module.
Step Description
1 Upon module boot-up, the Client Driver obtains configuration data from the MBTCP
controller tags. The configuration data obtained includes Ethernet configuration and the
Client Command List.
Special Commands can be issued directly from the CompactLogix processor using Event
Commands and Command Control. These command values are used by the Client
Driver to determine the types and order of commands to send to servers on the network.
2 After configuration, the Client Driver begins transmitting read and/or write commands to
server nodes on the network. If the Client Driver is writing data to a server, the data for
the write command is obtained from the module
’s internal database.
3 Once the specified server has successfully processed the command, it will return a
response message to the Client driver for processing.
4 Data received from a server in response to a read command is stored in the module’s
internal database.
5 Status is returned to the processor for each command in the Client Command List.