ProSoft Technology MVI56-104S - Manual (Page 128)

MVI56-104S ♦ ControlLogix Platform Reference
IEC 60870-5-104 Server Communication Module User Manual
Page 128 of 188
ProSoft Technology, Inc.
November 18, 2009
STARTDT & STOPDT
STARTDT (Start Data Transfer) and STOPDT (Stop Data Transfer) are used by
the client to control the data transfer from the MVI56-104S module. When the
connection is established, user data is not automatically enabled in the server
until it receives a STARTDT act request from the client. The server should
respond with a STARTDT con response to acknowledge the client request. Once
this procedure is concluded, the server can send monitor data to the client.
The client can interrupt the monitor data flow at any time sending a STOPDT act
command to the server.
In some circumstances the client unit may not support STARTDT and STOPDT
messages. The module may also be tested with simulator software that does not
support these features. During these situations, you may want to disable the
STARTDT and STOPDT features using the following parameter: