Campbell LoggerNet, Инструкция по эксплуатации, Страница: 446 / 580

Section 11. Utilities Installed with LoggerNet Admin and LoggerNet Remote
report a broken socket and so the watchdog is
necessary for reliability.
Rec Intv 2 This is an amount of time greater than 2 times the
expected interval between data records. It is just
longer than the longest period between records
the client would expect to receive from the
server. If the client goes longer than this interval
without receiving a new record then it should
close and reopen the socket, thus allowing the
server to recover if it has broken socket
connection.
Secure Rec The secure record action is taken when a Record
Rdy event occurs while the client is in the Wait
For Record state. Before the client sends an
acknowledgment to the server it should “secure”
the data record sufficiently so that if a power
failure or crash occurs the data will be safe.
Send Ack The send acknowledgment action is done in
response to the
Record Rdy event, after the
record is secured. In Send Ack the client forms
an acknowledgment record from information
taken from the data record and sends it to the
server.
Stop It is important to note that the Stop event could
occur at any time. If it occurs while in the
Session Open state then the socket should be
closed (
Close Session ) before program
termination.
Server State Diagram:
Key Word Description
Wait For Record Available In this state the server is waiting for the next
record to become available from the server’s data
record source.
Wait For Ack In this state the server is waiting for the client to
acknowledge that it has secured the record. If an
acknowledgment for the wrong record comes in,
the server will just continue to wait. After waiting
for a minute, the server will re-issue the data
record and wait again.
Advance Rec The advance record action is executed after the
server receives a valid acknowledgment record
from the client while in the
Wait For Ack Record
state. This is the point at which the server
recognizes that the client has secured a record
and the server relinquishes responsibility for the
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