ProSoft Technology MVI56-GEC - Manual (Page 82)

Reference MVI56-GEC ♦ ControlLogix Platform
User Manual Generic ASCII Ethernet Communication Module
Page 82 of 108 ProSoft Technology, Inc.
October 8, 2010
Network Data Transfer
In order for data to be transferred between the module and another device, a
TCP/IP connection must be made between a client and a server on the module.
The MVI56-GEC module contains five servers that listen on the user assigned
service ports waiting for a connection. When a client wishes to send data to the
module, it must open a TCP/IP connection to the module. After the connection is
established, either device can send and receive data. When either device is
finished with the connection, the connection must be closed. This operation can
be initiated from either end device.
The MVI56-GEC module servers and clients are configured to handle their
TCP/IP session independently. The user parameter Connection Timeout is
utilized to determine the amount of time a connection can remain idle before the
server will close the connection. If the parameter is set to 0, the server will not
perform the timeout logic and the socket will never be closed by the server on an
idle condition. If this feature is utilized, it can prevent connections that may be
lost and were not properly closed. After the connection is established, the ladder
logic should verify that the client had not been communicating for some time and
close the connection.