M241/251 opens 1 connection to check adapter identity and a second one for implicit exchanges.
The first connection is closed after 40 seconds as identity does not need to be checked continuously.
On some adapters (like ATV71 EtherNet/IP card VW3A3316), this first connection closure causes communication interruption of the second connection, too.
A workaround is to keep the first connection open by sending GetAttributeSingle requests for example every 5 seconds.
This can be done using function block EipDataExch from the EtherNet/IP Scanner library.
i_xMsgType input should be TRUE to use connected mode.
The first connection is closed after 40 seconds as identity does not need to be checked continuously.
On some adapters (like ATV71 EtherNet/IP card VW3A3316), this first connection closure causes communication interruption of the second connection, too.
A workaround is to keep the first connection open by sending GetAttributeSingle requests for example every 5 seconds.
This can be done using function block EipDataExch from the EtherNet/IP Scanner library.
i_xMsgType input should be TRUE to use connected mode.