Intermec DCS 300, Руководство пользователя, Страница: 426 / 452

DCS 300 User’s Manual
C-16
Retaining Transactions in Memory
AUX_Q
is an auxiliary queue in volatile memory. By default, the DCS 300 uses this
queue as a temporary holding place for transactions that are waiting to be sent to a
destination while the DCS 300 is waiting for an ACK from that destination.
AUX_Q
is used only in this situation:
•
The DCS 300 sends a transaction to a destination, the Hot Standby timeout begins
counting down, and the DCS 300 waits for an ACK.
•
While waiting, the DCS 300 receives another transaction for the destination. The
DCS 300 cannot send the transaction until it receives an ACK for the last
transaction, so the DCS 300 writes both transactions to
AUX_Q
.
•
All other transactions that subsequently arrive for the destination are written to
AUX_Q
.
•
If the DCS 300 receives the ACK before the Hot Standby timeout expires, the
DCS 300 sends the transactions in FIFO order from
AUX_Q
to the destination.
•
If the DCS 300 does not receive the ACK before the Hot Standby timeout expires,
the DCS 300 writes the contents of
AUX_Q
to the Hot Standby file.
You can specify the number of transactions the DCS 300 can hold in
AUX_Q
for each
application and DevComm before it writes the transactions to a Hot Standby file. To do
this, use the local interface to set the Transactions held in volatile memory parameter
on the Peer-to-Peer Destination Parameters dialog box to one of these values:
None
Transactions in
AUX_Q
are not entirely safe because they are held in volatile
memory. You can keep the DCS 300 from using
AUX_Q
by setting the parameter to
None, which forces the DCS 300 to write every transaction for a destination to that
destination’s Hot Standby file.
Unlimited
An unlimited number of transactions can be written to
AUX_Q
until either
the Hot Standby timeout expires or the DCS 300 sends all the transactions to the
destination.
Maximum (1 to 9999) When
AUX_Q
reaches its limit, the contents are written to the
Hot Standby file. The default for this parameter is 50.