Section 11. Utilities Installed with LoggerNet Admin and LoggerNet Remote
Session Open
exit: Close Session ( )
Rec Rdy
Session Failed/Report
Reg OK/Report
Server Registration
entry: Register Server ( )
Wait For Client Connection
entry: Open Session ( )
Wait for
Record
Available
Wait For Ack
entry: Send Rec ( )
Start Timer (60 sec)
exit: Stop Timer ( )
Wait For
Ack
Record
Bad Ack/Report
Server Registered
exit: Deregister Server ( )
Running
Session Opened/
Report
Ack/Report
(optional)
Advance Rec
TimeOut/
Report
Stop
Reg Failed/
Report
Start
Connect Failed/
Report
Data Export Server State Diagram
Key concepts from the state diagrams are shown in the following tables with
key words from the diagrams. In these definitions the “server” refers to the
Data Export data server and the “client” is the custom data retrieval client
application.
Client State Diagram:
Key Word Description
Test For Server Rdy With Socket APIs, usually there will be a
function used to open the socket. In this state, the
client program should attempt to open the socket.
If Open Failed, the client should wait 5 seconds
and try again.
Wait For Record In this state the client is waiting for the next data
record from the server. When a record is received
it should be “secured” (saved to disk or
database), then an acknowledgment should be
sent back to the server. Once the server has
processed the acknowledgment it will not send
that record again. The client should use a
watchdog timer while waiting for a data record. If
the client is in the Wait For Record state for
longer than expected (RecIntv2) then it should
assume that the server has died and close the
session. This watchdog operation may be difficult
to implement, but it seems that some
implementations of sockets do not properly
11-17
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