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.
Diterbitkan untuk:Schneider Electric Indonesia