ProSoft Technology MVI46-DFNT - Manual (Page 75)

MVI46-DFNT ♦ SLC Platform Reference
EtherNet/IP Client/Server Communication Module User Manual
ProSoft Technology, Inc. Page 75 of 177
October 12, 2010
4.2.3 Data Flow between MVI46-DFNT Module and SLC Processor
The following discussion outlines the flow of data between the two pieces of
hardware (SLC processor and MVI46-DFNT module) and other nodes on the
TCP/IP network under the module’s different operating modes. The module
contains both servers and a client. The servers accept TCP/IP connections on
service port AF12. The client establishes connections to service port AF12
(hexadecimal) on other EtherNet/IP servers.
The following topics discuss the operation of the server and client drivers.
Server Driver
The Server Driver allows the MVI46-DFNT module to respond to data read and
write commands issued by clients on the EtherNet/IP network using explicit
messaging. The following flow chart and associated table describe the flow of
data into and out of the module.
Step Description
1 The server driver receives the configuration information from the configuration file on the
Compact Flash Disk, and the module initializes the servers.
2 A Host device, such as a SLC processor, RSLinx or an HMI application issues a read or
write command to the module. The server driver qualifies the message before accepting
it into the module.
3 After the module accepts the command, the data is immediately transferred to or from
the internal database in the module. If the command is a read command, the data is
read out of the database and a response message is built. If the command is a write
command, the data is written directly into the database and the M1 file and a response
message is built.
4 After the data processing has been completed in Step 3, the response is issued to the
originating master node.
5 Status data for the servers is passed to the processor under ladder logic control using
the command control data area in the M1 file.